View Full Version : 1979 Viking build

02-15-2021, 02:37 PM
Three times a charm so they say. As of today the hull sits bare, cap separated, all core and transom removed. Layup is going to be balsa core set in ATC B72 Corebond with Derakane 8084P Vinylester for resin. Transom, stringers and floor will all be done in Coosa. Transom will also be set in Corebond. Prior to setting the core and transom in place I will be covering the entire inside of the hull and transom with 1708 before using corebond to set in the core and transom respectively after wetting out with resin. Some knees are going in, and four stringers. Core will run up farther than original. This boat is getting a full interior and will be mostly something to cruise in and feel the fresh air at speed. Power is a 98 200efi that will be getting a build thread of its own when the hull is complete. I want the quality to be as high as I can manage and this build to last so if you have ANY suggestions or want to suggest a different tack im open to any and all of that. I read everything I could about doing this and called as many pro shops as I could. I cant thank S&F members for your content here and answers to my endless questions in other threads, and there will be more so I really appreciate the support. S&F is AWESOME!

Heres some pics of its current state. There is some holes and hull damage from the previous owner/s. I did not strip this hull down but now I have to repair it. Plan is to grind the damaged areas to solid glass and use packing tape or cardboard with parchment on the underside of any holes and glass over them. Would I be best to do this with a single layer of 1708 or multiple layers of CSM? I bought 15 yards of 1708 and 10 yards of CSM. Take a look and let me know what you think I should do about repairing the holes and those gouges in the pics below. If you look at the first pic you can see near the front a patch with no gel, and the spot inside the hull from the top you can sorta see it, this was a previously repaired hole I will be removing this repair and starting fresh. Thanks all







02-15-2021, 04:10 PM
Okay so new info is already coming at me ;) Critique this layup or give it thumbs up;

After the hull is repaired and a full layer of 1708 is laid up with the vinylester and cured. I will smooth and flatten the 1708 covered hull with a quick scuff then;

Corebond over the cured vinyester
prime balsa core with GP resin timed to kick at the same time as corebond
set core in and let cure
Then back to using vinyester for the rest of the layup.

Do I have to prime the Coosa before using corebond too?

02-15-2021, 05:47 PM

02-16-2021, 11:28 AM
Dang! The last owner did you a huge favor taking that entire hull down to the woven roving! That just cut out the worst part of the rebuild process, putting it back together is fun. Great to see another one of these saved, looking forward to seeing this come together.

I wish I would've added more core in mine. Mainly at the point in front of the floor. That seems like a high stress point, mine even had a repair done at the factory in that spot. If I do another one I will have core come up into the first chine right at the forward edge of the floor and continue along that "body line" until a few feet short of the nose. That way there's no hard edge at the front edge of the floor.

Can't help with the different chemical questions, but the experts will be along shortly.

02-16-2021, 12:35 PM
Sounds good to me....Just scuff and clean the coosa.

02-16-2021, 04:12 PM
Thank you both! We just pulled it inside the shop and materials are to be here on Thursday. Order of operations for starters is to make a cradle, clean and degrease the hull first with soap and water and a scrub brush. Follow that up with a thorough acetone wipe. Then we will grind some tooth into the glass and using air and vacuum only to clean, no acetone to aid bond by leaving the fibers fibery for lack of a better term. Then we lay the first layer of 1708 down with VE and leave to cure. Method to this approach sound healthy?

The only thing I go back forth on is the acetone. In auto body work we wipe all the time with reducer/thinner etc to keep surfaces perfectly clean. It feels a bit out of my norm to grind and not use a chemical wash after before bonding material.

02-16-2021, 04:28 PM
Styrene is the only one that will make old resin sticky. It's all I have ever used for wipedown. But it's nasty to deal with fumes and skin sensitivity wise. Acetone just cleans oils and may attract moisture since it has a hi evap rate. Fresh grind is prob the best. Grind, blow clean with good clean air and glass it up soon.

02-16-2021, 04:43 PM
In auto paint the surface contaminants can get ground into deeper layers even the the metal and cause bonding/bubbling issues over time so the degrease is to ensure your not sanding any nasties down into the work. I will be careful with the prep, its critical I know this. The derakane is also supposedly the stickiest VE available. Hope it all goes well

As for the core Tnels I had a couple of good chats with one of John Spaeths guys who guided me with materials and process and he said core up to 6" below the bow eye. He also said dont put any wood at all in the bow eye layup, just lots of glass. Thought that a neat tip ive had a few loose ones now.

02-17-2021, 10:55 AM
Splashwell delete. Thinking this is the better way. Will tie in the top of splashwell to the transom maybe make a knee brace that the splashwell delete ties into.

aside from that are there any concerns I should know of if I delete the splashwell? Seastar pro steering, seastar Jack plate. Any tilt/trim or fitment concerns?

02-17-2021, 12:12 PM
If you're running a jack plate you won't have any worries about the splash well. My plate is a 4" set back and the SeaStar steering is nowhere near the splash well. My only problem is the steering ram will hit the transom if I trim too high with the plate down.

You'll be able to fit a bigger tank and have an easier time rigging with no splash well.

02-17-2021, 01:13 PM
I want to make a huge tank. I like to cruise some distance. I’m planning 4” setback as well I want to keep the porpoising to a minimum. Splash well delete is looking to be a go unless anyone has any negatives to add?

02-18-2021, 01:32 PM
just an example of how I did my knees and tied the top cap stingers into the transom, never were that I know of direct from Hydrostream. Really easy to do with a splashwell delete, but wouldn't be hard to do with keeping the splashwell either.

02-18-2021, 03:10 PM
I dig that. I will be doing same/similar to mine for sure. Thanks fellas!

02-18-2021, 10:32 PM
Lake, here is an idea of how everything sits in relation to the splash well/transom. My plate is all the way up and trimmed to the max here. Plenty of room even without the well. Just depends on how you run your steering lines.


02-18-2021, 10:48 PM
Perfect thanks! I’m going to run bulkhead fittings to tidy up the steering lines. I picked up the resin, coosa and a bunch of other stuff today. Fired up over this

02-19-2021, 07:04 PM
Started on the cradle today and ran into a bit of gridlock. We measured carefully with plumb bobs at a few stages side to side on the hull. Then we separated the cap, washed and vacíd the glass, and braced accross to our measurement dimensions. The thing that stopped us was if I lift on the transom even a little bit the entire hull flexes and shifts, a LOT.

Is there a drawing or some dimensions I can reference so I get the cradle cut to correct spec?


02-20-2021, 12:35 AM
Hello Lake, to get your hull back in specs, use a waterlevel to get everything on the money. mark a location under the strake at the rear of the hull, install a screw about 4" down from the edge of starboard strake, now go to the other side an use the water level to tell you where to mount the next screw, under the port strake now you just shim to get the 2 areas level, the pins are now level and you can measure up with a ruler, add reduce shims as needed. Now at the transom measure down from known marks/hull features, end of strakes, side chimes, etc. Mark one side 4'down as a reference point than transfer to other side an repeat, install screw where pin becomes level, not just measure .distance to have it perfectly level, straps can be used to help hold down area but don get crazy on the load. Any point that has a matching point on the other side can be used as a level point to insure no twist, Get a 3/8 clear hose and fill to 1' from each end, take your time an hull will be spot on ,old boatbuilder trick but is the only way to good, cheap and accurate, John also when time, roll your core on half barrel to open it u for good access, also grind coosa and then blow out the pores[full of dust] when applying first coat of resin use a spreader the push resin into the cores to brake the mechanical tension, it will improve your bonding. Its easier than said and works great, I use this system always, John

02-20-2021, 07:50 AM
That’s excellent advice thank you! The only thing I’m a little unsure of is the screws? You suggest a screw through the hull into the cradle? Or through the hull only to use as a reference point? Can I not put a marker dot to reference and avoid the screw or am I missing something?

the balsa over a barrel to improve resin saturation is an excellent tip I really appreciate that one and will be doing this for sure. I was very hesitant to use balsa I wanted a fully synthetic build to prevent any future rot but the strength and the thinking that when properly sealed the balsa will last won me over in the end.

02-20-2021, 04:44 PM
Can I use core-bond to set the stringers in? Can I use core-bond to fill gaps/voids like in between the core and the edge of the pad, and in between the transom edges to hull? Basically places where I see people using peanut butter, do you recommend core-bond as a suitable substitute?

02-20-2021, 10:54 PM
Lake, don't put a screw into the hull, put it in the cradle, let the shank stick out as a starting point, a dot will work, just easier to line a ruler up on a screw shank. When you bend the balsa over a barrel it lets you get resin fully into the core by opening up the blocks, always grind and blow off coosa, scraping a coat of resin will penatrate into the thousand of tiny holes and improve the bond. I use micro spheres[bubbles] mixed into resin as a putty for filling /faring. I've never used corebond so can't help on that, I've always laid core into a mat and resin base. John

02-21-2021, 05:25 AM
I understand the barrel and core wetting procedure im good with that and its a great tip! I understand the water level I remember seeing crews installing tee bar ceiling using them I’m good with the level concept.

What I’m a bit unsure of is how to layout the cradle because the hull is bare and floppy. So while I can duplicate the shape of the hull to plywood at sections and cut them out ok. I don’t know what shape the hull is supposed to ideally be. I was thinking to use a large scribe similar to log cabin building to transfer the shape of the hull to sections of plywood for the cradle then I guess I’ll have to do my best with the water level getting both sides symmetrical. I’m thinking if I start with the pad ensuring it’s perfectly flat and level then using the water level and shim up from there to support the chines and finally do a visual inspection of the rub rail position when that’s all done and see how straight it is. I can’t think of anything else to do really. Wish me luck we start on this tomorrow

02-21-2021, 11:17 PM
I don't know if hull is twisted or wavey, but twisted is easy, turn hull over, use water level at trans first, level out trans by using outside chimes, block to hold shape and move up the hull say 10', mark both sides and level up, use scrap plywood to scribe pattern for cradle, bow up or down doesn't matter as hull will be straight, you can add to front cradle to get it sitting like you want after you flip it over, this should get you started, make patterns it will save you a lot of plywood, john

02-22-2021, 09:13 AM
Make a fairly sturdy cradle that is level and straight> basically boards running just longitudinally, place hull into cradle. Check to see where the hull is not making contact. try and make it the same from side to side with some moderate weight and wedges. Build structure, floor etc.. Flip boat, sharpen strakes and blueprint hull to same specs from side to side. These hulls were never built to exacting specs nor did they stay exactly straight or true to the centerline over their lifetime. (twist) Just re-glassing the hull will pull the shape out of true when the glass shrinks and warps. I had a friend weld an alum cradle out of scrap when I did mine. Wood will work good too. But choose good straight boards, bolt and screw it together and check with a string, laser, or the water level while building it. If you make plywood templates for side to side, pick one side and just mirror for the other side. Lot of ways to do it. Some even make a cradle on the boats trailer frame. jm2cts.

02-22-2021, 01:39 PM
Thatís valuable guidance thanks again. We made the first plywood piece to cradle the rear where all the angles are because that area does not shift when we lift and move the hull around. We slid the boat off the trailer onto the first cross brace and are working on number two. Looks like things are level and true. Happy thus far. Gratuitous pics


02-22-2021, 03:38 PM
Good start with a solid reference point.

03-02-2021, 04:55 PM
Got the cradle pretty much wrapped up today. Attached a pic, we are thinking of using some expanding foam to fit the hull really tight to the braces, we have some semi rigid two part low expansion stuff for this. One of my helpers is a window man so he has the right product.

Starting to think about glassing and will do a layer of 1708 over the entire hull but first a few patches. For these some guidance is appreciated. Was thinking CSM in 3 or 5 layers? Grind the damage and holes down to allow for glass to be built back up yes? Also what are these holes above the drain hole on the radius part of the transom area in this pic for? Cant think of any reason for them


03-02-2021, 05:19 PM
Might use some mat and 1708 to patch. Depends on the thickness of hull area. Holes, I have no idea.

03-05-2021, 07:59 PM

We added some casters and lifted the hull out of the cradle today. Pic to show how we set it up. There are a bunch more smaller detailed supports not shown. We used door jams for braces because free

03-14-2021, 03:21 PM
We finally wrapped up the cradle today. The hull had some twist in it from sitting without the core for a few years. We worked very hard to true it up as best we could but there are some warps on the chines for/aft that appear to be manufacture issues not warp issues from sitting. That said we have all chines within 1/4" total so 1/8" per side of true and thats only in the one spot about midway down the starboard side. We referenced 6 points per side so 12 reference points in total and most are identical or 1/16" variance side/side.

To make the cradle completely locked in this place we hoisted the boat up and used premix fiberglass to line the cradle supports and placed parchment paper over top then lowered the hull back down which really makes it very stable in the cradle now. So next weekend we are going to begin laying in some glass repairs and see how we make out.

03-14-2021, 04:03 PM
Dang! You sure took the cradle further than I did. Sounds like its going to be solid.

03-14-2021, 05:14 PM
Looking good, almost time to let the beatings begin!

03-14-2021, 06:26 PM
No i donít think I went further really in terms of design I was heavily influenced by yours. The key difference is I need to be able to move the cradle in and out of the shop as well as lift the boat in and out without compromising it. This is where the differences are. I might make it into a storage cradle after the build is done.

There will be plenty of people around this thing too so I had to make sure it was fool proof in the sense that if you drop the boat in, it fits spot on and thereís no shimming etc nec. Plus I could see more hulls being done in this thing I have a few friends with vkings and Valeroís.

Iím really wanting to get started laying this thing up though. Been hard to get many days on it so far. We thought we had more time but work stuff got busy.

03-17-2021, 02:25 PM
First piece of glass is in! Little single layer CSM patch along with a few test pieces on the bench. Went smooth we mixed in 2.5% mekp at 65 degrees and it took about an hour to mostly cure, about 30 mins to gel up. I put some parchment and packing tape under the hole and tabbed in the patch over worked slick. I also left about 1/2" of the derakane Vinylester in the mixing cup to see how strong the resin alone would be and wow! This derakane is TOUGH stuff. Even smashing it with a hammer wont break it. Very impressed.

Adhesion also seems to be extremely strong I could not pry any from the dirty unprepped wood I tried some CSM and 1708 test pieces on. This whole first round makes me feel a lot more comfortable about the product and getting more serious with the glassing the hull this coming weekend.

I also have to say the smell is really nice, it smells like finely refined bondo for lack of a better description. I had a body shop eons ago and that old familiar scent was a welcome thing here. Not sure how others feel about it but I really like it. I added a pic of how good the adhesion of this Derakane is. I had a little on my finger and thumb after tabbing and when it began to kick, well look at the pic and see. So fine and so much grip. Impressed so far with it



03-17-2021, 04:30 PM
Derakane is a hi quality vinyl hybrid. Really intended as a chemical resistant product. I made salt and chlorine holding tanks with it long ago for a water treatment plant. It does smell different than reg vinyl or poly. A bispherenol based resin. Not much styrene in it.

03-17-2021, 05:51 PM
That’s exactly what the sales rep said. Made to bond to anything including concrete for commercial use with extreme chemical resistant properties. Marine use is merely a bonus. I figure it like this; I have this chance to build this thing so I wanted the best materials I could get to make it all that more worthwhile. I really went back and forth with the core though. Ended up choosing balsa and feel it will be good. Time will tell

03-17-2021, 10:13 PM
First piece of glass going in is a good feeling!

03-18-2021, 05:45 PM
How many layers should I lay in for hull holes? I have csm and 1708

03-21-2021, 11:19 AM
Would still like to know any thoughts on how much glass to lay in before core. We were thinking two layers of 1708 in the core and pad area and one layer of 1708 over the entire hull. Yesterday the plan was to do most of this but we had some sanding to do first. We started off by giving it a good wipe down with acetone. Then we moved to sanding and it's quite a surprise how once you start sanding in the core/pad area there was air pockets and cabosil in places quite thick and some scratches from whoever removed it we had to feather out etc. Kept finding lots of places that needed more sanding and grinding which took a lot longer to clean up and prep than I thought it would. We did get it all done and the entire inside of the hull has been hit with 26 grit and is ready for the lay up. We started in the thin spots and the holes in the transom with a single layer of CSM and that was as far as we got yesterday. Going to sand those down and add another couple of layers of CSM over those spots before moving onto 1708.

Fire away if you see anything or think of anything Im doing wrong.


03-21-2021, 07:15 PM
I vacuum bagged my core to 12 oz glass with thick resin as well. But if hand layup 1708 should be good at one layer. One layer over the top. Go twice on transitions and ya good. Top side of the core needs to be the strong side, water pushing up into the hull. Anyway, that's my opi

03-22-2021, 08:37 AM
Thanks that’s pretty much my thoughts on why I was going to add a second laying under the core and pad area. I’ve owned enough of these to see where they chip off underneath and it’s at the edges of the pad and chines mostly. So unless anyone has other to say RJ has the call two layers of 1708 in all the edges and then core. Then glass over top 1708 with csm on top for finish. Anywhere that looks like a good spot to add more I will. I’d rather add fifty pounds to the hull to make it wake board wave proof than not. Want it to last

03-22-2021, 08:57 AM
I would not bother with 2 layers of 1708 on the bottom side of the core to be clear. One layer under core and one over the top with 2 layers at the edges and on the transition up the stringers. On my vking I ran it light last year and beat it good on some windy days (never got around to finishing, put the motor on and ran it all year!!). None of my work gave way. I only did 12 oz biax under the core, then one layer of 1708 over the core. My floor was 1/2 ply with 6oz cloth on the under side and over the top side once bedded into the hull. I wanted to see if the floor to hull area would crack at all or separate but it did not. So this week/next week I will put a 10 inch strip of 1708 at the floor/hull area and up under the bow where the core meets the hull. My hull is very thin so up where your feet are under the bow the hull is flexible on the sides where the core ends and I was going to stiffen it up some with 1708.

03-22-2021, 09:06 AM
Build it how you intend to use it. I built mine stout and don't regret it at all. Add glass where you think it needs it. Cover the edges of the 1708 with some torn mat. (called tailing, adds shear strength) I have jumped mine and ran some rough water. No cracks...Your plan sounds fine.

03-22-2021, 09:32 AM
Awesome tips thank you! Tailing will be done on all 1708. You guys rock

03-22-2021, 10:27 PM
My boat got about 3-4 layers of CSM in the patches, full single layer of 1708 across entire bottom after patching.

03-23-2021, 06:02 AM
My one strake in particular port side where the floor sits was sliced with the grinder right to the gel. I feathered it out so there was no hard edge and put two layers of Csm and yesterday I ran a single 9” wide strip of 1708 over that. I was surprised at how much more resin the 1708 took vs the csm. It’s at least 4-5 times more. Anyways I will tail the 1708 with csm and to add balance I will do the same 1708 strip down the port side. Once cured I will feather this all in and do another layer of 1708 over the whole bottom. Maybe overkill but it’s making me feel better about the build.

one thing I have already noticed is the derakane is considerably harder when grinding vs the existing glass. Makes feathering a little tricky but I like the strength gain

I really appreciate all you guys input. I’ll update some pics soon

03-28-2021, 07:54 AM

We laid up csm in thin areas a few layers or more. Instead of running two layers of 1708 over the bottom we came up with an overlapping system that put three layers of 1708 over the spots I was worried about and only one layer over the area that will be under the core. We also tailed ( great tip thanks xstream ) all the 1708 at the seams before laying over more except for the two main pieces under the core area because we overlapped those 4” and thought it was good. For whatever reason this hull seems to have the best quality existing glass in the pad area and under the core. It’s really thick there I drilled a tiny test hole it was almost 1/4” thick with two layers of roving. We think this hull may have been restored once before.

it’s a relief to have this part of the build done. It was the only part of the process we were scratching our heads over. Now that we have a sound hull I hope next weekend to be laying in core and starting on the transom. We are going to lay a few layers of 1708 on the inside of the transom area before putting coosa in. I have an interlocking plan for tabbing the 1708 into the bottom and sides that should really strengthen up that area.

03-28-2021, 10:04 AM
Looking good man..

03-30-2021, 04:12 PM
Had a few hours today to lay in more glass. Not being totally sure how to lay over the existing holes I ground a smooth bevel about 2" radius around each hole halfway through existing glass and laid in three layers of CSM each one extending out an inch or two and sanded them now flush with existing prior to laying in fresh 1708. Did the same with the transom which is getting 1708 next session. Starting to get the hang of this now



03-30-2021, 06:38 PM
Looks great! I almost miss this part. Instead I'm over here pulling out what little hair I have left waiting for parts from other people while ice is going off local lakes.

03-30-2021, 07:07 PM
Trade ya :D

In all seriousness I understand what your saying. This is now fun to do and I want to work on it everyday even when I can’t. I have always loved to work but not always loved the work I had to do. This is chosen work and I’m lovin every minute of it. Hope to be laying core this weekend

04-01-2021, 11:10 AM
How many layers of 1708 should I put on the inside skin of the transom before I lay the transom coosa in? I ran one and was thinking three?


04-01-2021, 01:33 PM
I only did one on mine. Then used CSM to bond transom wood to hull. I did two full layers of 1708 on the inside though, with 2 overlapping layers tabbing in first. It's beyond my pay grade, but I think 3 would be overkill.

Looks like you're doing very good clean glass work!

04-01-2021, 04:32 PM
Thanks much! Well we did two so two it is. We are basically taking the approach of when in doubt? Add more glass. That said we don’t want to waste time doing what’s not necessary so I guess we will stop at two and that means tomorrow we are laying in the transom! First time we get to play with the coosa. Thinking two layers of 3/4” and one of 1/2”

Just realized we will also be using core bond for the first time tomorrow too

04-02-2021, 04:08 PM
Got the transom pieces cut and fit today and that’s as much time as we had. Plus I wasn’t sure if I should drill relief holes in the coosa because we are using corebond. Supplier said use a 1/4” v notch trowel, no holes, and go easy on weight he said 20psi was plenty.

we cut three layers of coosa; 2x 3/4” and 1x 1/2”. Going to laminate the 1/2” in the middle. What say you guys about relief holes yay or nay?

04-03-2021, 08:51 AM
Won't hurt a thing. May release some trapped air. JM2cts. You prob have a 1/4'' of glass on the trans face to take the load of the engine and jack plate. Should be good. The transom face spreads the load from the engine and jackplate forces. Also spreads the load from the bolts clamping forces. All this load spreading is preventing any compression of the softer coosa core. Make it the same on the inside where the bolts go thru.

04-03-2021, 09:12 AM
Thanks that’s helpful I might as well drill then if there’s no loss. I wonder if I should toss a third layer of 1708 on the transom skin before laying in the coosa? I was also thinking to add sleeves for the Jack plate bolt holes to take some load off the coosa. It’s so light it’s kinda freaky thinking of what power it has to hang onto

04-03-2021, 10:23 AM
After 2 lays plus original what do you have for thickness? 1/4'' is usually good, more wont hurt. I don't sleeve the bolts or use alum plates to mount anything. Lg washers on the bolts is enough. Don't need to crank the trans bolts either. Use a tq wrench tp get them even. 20-30#'s is usually enough. Check them again later for a re-tq.

04-03-2021, 11:52 AM
I’m not sure how thick it is I’ll have to measure it. Good tip re torque spec I know it doesn’t take much but I wasn’t sure on torque. That’s good to know

04-03-2021, 08:28 PM
Lake, man it's so cool to see your build starting to come together as mine is wrapping up. I love these rebuild threads on this site!

As for checking torque I just found this product being used by one of the airplane builders I follow on YouTube (Mike Patey) great page to follow. It's a seal/indicator showing if something has turned. It doesn't hold anything like lock tight, just shows if it moves. I have it on all the steering component hardware as well as engine mounts. Goes on kinda like that cake decoration icing you buy in a tube. Drys in an hour and cures in 24. Resists vibration, heat, cold, etc. Boeing uses it during assembly. Lots of color options to choose from too, I grabbed blue to match the boat.

So now I have a quick reference to look at when doing a pre launch walk around of the boat.




04-04-2021, 06:55 AM
I enjoy the build threads too. I’m glad to finally be offering up some entertaining content after years of endless questions LOL. That dykem seal cracker looks cool and handy I’ll add that to my process for certain things for sure, thanks for that. Hope to get back at it a little bit tomorrow. At least get the transom block laminated and then hopefully lay it in the hull the following day

04-05-2021, 05:48 PM
Transom outer skin is 3/16Ē right at the top measured with calipers but it is thicker in the middle so itís around a 1/4Ē for the most part Iím sure. Donít think Iím going to add another layer of 1708 but ya never know. I made some unistrut clamps today for this. Seems to hold well. I have a piece of 3/4Ē plywood attached to the cradle that is the same angle as the transom so I can clamp it flat and strong.

I donít have a lot of time for the boat this week so it will be a bit slow until next week I should have more time available.



04-10-2021, 06:45 PM
Looking good, I was slacking and peeked at your build, looks like I better get a move on or your gonna pass me up.

04-23-2021, 07:54 PM
Finally got back at this for a few hours today. In some ways these delays are helpful because it gives me more time to think and plan and in other ways the delays drive me nuts. Took about three hours of messing around finding all the tools and materials getting them set up ready to start laying up stuff again. So the thinking is with the coosa transom I really donít want any chance for issues so we added a third layer of 1708 inside the transom skin and will be adding a fourth on the outside as well as a layer or two of csm for finishing. Might be overkill but it makes me feel safer about this process.

We also bonded two of the three coosa layers together today using a 1/4Ē v notch trowel and we did just like Xstream advised. We used 40 grit on a block and scuffed diagonally in both directions to rough the coosa surface and then used air and blew it out really well. We spread the core bond on both panels first flat by pushing it hard into the coosa then one sheet horizontal notches and the other vertical notches. Placed the two coosa panels on a heavy table with parchment and a sheet of 3/4Ē ply with concrete blocks over for weight. The core bond didnít compress as much as I thought it would but it really seems to bond very well. Tomorrow we will add the third layer into the coosa layup and then bond it into the hull. Felt great to get back to this

04-24-2021, 05:13 PM
We got ourselves a transom! I also laid in another 5í section of 1708 in the front floor area where the damage was to the hull. I was going to do the whole thing but after some of you said it wasnít nec I decided against it but today I just couldnít resist because this area seems prone to damage from other resto threads I have seen so I beefed it up and it looks good for core now.

we also did a test with the core bond over my very first test pieces of csm and 1708 on plywood. I did no prep to the old glass or the plywood I bonded down. Just one coat of core bond and pressed by hand the pieces of plywood down and I could not pry them apart no matter what I tried. I snapped both pieces of plywood apart in the glue and the core bond held. I was shocked that the grip was that high especially with no prep.

thatís all for now hope to get some more done next week. Itís nice to finally be building some of this thing instead of repairing.

04-24-2021, 06:04 PM
Looks good! Some days I wish I added another 3/4" to my transom. But I think my giant knees will pick up where more wood leaves off. Plus I'm not going crazy with power.

You're doing very quality work from what I can see.


04-24-2021, 06:19 PM
With plywood dual 3/4 is plenty. With the coosa being so light and much easier to compress the further the span and thicker the glass the less leverage the bolts will have on the coosa so this is why I did it. It’s two layers 3/4 and one layer 1/2 in the middle of the two.

Thanks for the kind words on the build. We are trying to do our best but this is my first boat resto so it’s been a learning curve. Goal is to have a strong safe fun boat that will last as long as I do lol

04-24-2021, 07:13 PM
We are trying to do our best but this is my first boat resto so it’s been a learning curve. Goal is to have a strong safe fun boat that will last as long as I do lol

I am 100% in the same boat. Pun intended haha.:D

05-01-2021, 05:57 PM
Got some core in today! I can see why it’s called core bond and not transom bond. While I was quite pleased with the transom bond and install the corebond with the gp primed balsa core is really incredible. The core bond squeezed up between the balsa and I faired in the edges with the corebond all in one session and its a completely void free pad now. Very slick product. Some pics for you guys

averep thanks for the tip priming the balsa spread open over a barrel. We did it lengthwise over a piece of pvc pipe and the wide side over a barrel and brushed resin in between all the pieces. Worked great!

Edit- added a pic of the hull after all glass repairs done before core

05-07-2021, 02:30 PM
Getting back to work tomorrow and wondering about the core and stringers? Initially I was thinking lay in all the core, glass it, then do the stringers. Now that the core is going in it looks like it will be a very hard edge to wrap the 1708 around from the sides of the core down to the core in the pad unless i use a lot of thickened resin which will make the stringer bedding afterwards, not ideal. What do you guys suggest here? I was thinking maybe grind the edge of core where it meets the pad to a rounder shape but worry about thinning the core down especially close to the pad? Or should I lay a piece of 1708 or two over the pad now as it is in above pics and lay the stringers on top of that at the edge of pad and then lay the side core up against the side of the stringers? Then glass that all in? Am I making sense? LOL lots of ways to do this, advice would be nice.

I could add a second layer of core in the pad like Tnels did that will bring the hard to cover edge up making it a lot easier. Hmmmm

05-08-2021, 06:25 AM
Getting back to work tomorrow and wondering about the core and stringers? Initially I was thinking lay in all the core, glass it, then do the stringers. Now that the core is going in it looks like it will be a very hard edge to wrap the 1708 around from the sides of the core down to the core in the pad unless i use a lot of thickened resin which will make the stringer bedding afterwards, not ideal. What do you guys suggest here? I was thinking maybe grind the edge of core where it meets the pad to a rounder shape but worry about thinning the core down especially close to the pad? Or should I lay a piece of 1708 or two over the pad now as it is in above pics and lay the stringers on top of that at the edge of pad and then lay the side core up against the side of the stringers? Then glass that all in? Am I making sense? LOL lots of ways to do this, advice would be nice.

I could add a second layer of core in the pad like Tnels did that will bring the hard to cover edge up making it a lot easier. HmmmmI did it just like you were initially thinking to do it, lots of thickened resin for the radius. It is a pain in the but especially if you add all the fingers that branch off the main stringers like I did. So far the happiest day of my restore was being done with the stringers, it was the most tedious time consuming part of the project so far. What are you going to use for the stringers?

05-08-2021, 07:02 AM
I’m using 1/2” coosa for stringers and floor. I slept on it and my thinking is to either add the second layer of core or glass over the pad core tabbed 2” above and then bed the stringers and the side pieces of core in at the same time with corebond. I did some test fitting yesterday I can make a really clean tight fit if I go this way. Today’s boat work got pushed aside once again which is unfortunate/fortunate because it leaves me more time to figure out the best method.

More suggestions welcome :D

05-08-2021, 07:18 AM
I’m using 1/2” coosa for stringers and floor. I slept on it and my thinking is to either add the second layer of core or glass over the pad core tabbed 2” above and then bed the stringers and the side pieces of core in at the same time with corebond. I did some test fitting yesterday I can make a really clean tight fit if I go this way. Today’s boat work got pushed aside once again which is unfortunate/fortunate because it leaves me more time to figure out the best method.

More suggestions welcome :D Don’t feel bad, my boat work got pushed aside also because of this new fishing boat I bought.

05-08-2021, 10:11 AM
Or should I lay a piece of 1708 or two over the pad now as it is in above pics and lay the stringers on top of that at the edge of pad and then lay the side core up against the side of the stringers? Then glass that all in?

If you don't want a second layer of core in the pad I think this is the best way. I copied "Out-a-Site"s factory built comp hull that had doubled up core in the pad. I knew mine would end up on the heavy side so I liked the idea of more support in the pad to carry the extra 150lbs. Also, the second layer of core in the pad gave the outer core a nice stop to rest against when bonding. The stringers would do the same if you go that route, but that might not even be a problem with core bond.

I did build a sample part using leftover material. Layup as follows(1708, CSM, 1/2" balsa, 1708) the second layer of core was laid up (CSM, 1/2" balsa, 1708). There is a considerable difference is stiffness.

From the amateur builder point of view, I liked the idea when I laid 1708 over the core I could do one continuous piece. So each strand of the weave would extend from the first chine completely across the core to the other first chine. I'm my head thats stronger than multiple pieces of 1708. But I could be totally off base. And either way is still going to be considerably stronger than the factory built it. Heck, mine had just chopper gun over most the core.


05-08-2021, 08:59 PM
I’m using 5/8” balsa so doubling that up seems a bit much. I’m thinking the route you suggested is sounding best so far because I can lay the stringers and the core in together with core bond and it will be void free and easier to glass up after. I’ll end up with a couple layers of 1708 over the pad this way as well which sounds comforting.

thanks for the info I’ll ruminate over it all lol