Mirage Transom Repair

[jamoore]

Thought I would share my suffering with all as I re-do the transom on my Mirage. B-Mac inspired me with his thread so I got off my lazy butt and started what I had been putting off.

First, a little history. I bought this boat as a bare hull on a trailer several years ago. Bought it at a drag race and the purchase was a story all unto itself. Anyway, although it looked pretty good, it was rode hard and put up wet but the price was right and I wanted a project. I didn't have time to start it right away so I covered it for a year. Then I stripped the paint (turned out to be 2 paint jobs on it) and re-did the whole thing. Added a second seat and rigged it as you see here.

Don't have a lot of time/ hours on it since the re-do. Never abused it and was still feeling it out. Started noticing a crack across the top of the transom. Seemed to get a little bigger each time I had it out. Last summer I knew what had to be done so I put it up early until I could get around to it. Now the fun begins. Sure wish I had known the transom was soft when I re-did the boat the first time. Seemed solid to the touch. Wasn't until the motor was on and started running it that it showed itself.

Based on what I have found out about the boat by working on it, and now that I have partially removed the transom, I strongly suspect this is not a true Mirage but probably a splash somebody made. The transom seems to be made of exterior plywood, 2 layers of 3/4. Nothing between the layers. Staples holding the two layers of plywood together.

I will post pictures and updates as I go along. Time is scarce for me so it may not move along as fast as you or I might like but I will keep plugging along. Hope you enjoy, I know I won't!!!!

Joey
1st. picture of it before the surgery, hate to do this

[jamoore]

another picture

[jamoore]

the crack

[jamoore]

Cutting the deck to get at the transom

[jamoore]

1st layer of plywood coming out, looks to be 3/4" exterior plywood. What CRAP!!!

[jamoore]

Rusty staples holding the two layers of plywood together!

[jamoore]

Took most of 1 day to de-rig and get to this point. This is what is left of one layer of soggy plywood. Came out hard, had to fight it with pry bars, grinders, cut off wheels ect.

[jamoore]

second layer of soggy 3/4" ply coming out.

[jamoore]

All the old wood is out, new sheet of marine ply is on hand!

[B.Mac]

Lookin' great!!! That's one sweet looking rig......I love the paint scheme.....Mirage or not....that's a sweet rig!!!

It's amazing what some builders will do to save some time.....
Staples in the transom???? Whoever did that needs to be stood up straight and backslapped!!:eek:

Nice work!!! Let's see some more!!! C'mon now get back at it!!! The fun part is yet to begin!!!
B.MAC:D

[jamoore]

I wish I had known the transom was soft when I stripped the boat and painted it the first time. Would have been easier to fix then. Hated to have to cut my paint job up.

I am sitting here with cuts and scrapes all over my hands. Not to mention the fiberglass rash on my forearms. Really felt good at clean up time!

I did get the first layer of wood back in this weekend. Will have a couple more pictures up later today. Slowly making progress. At least it will be solid and done right. Even after cutting the top off, I had to drill the rivets across the back and separate the hull and deck there for a little more clearance.

I was serious when I said you inspired me to get moving on this project. Yours was a major task and turned out great. Your pictures and step by step commentary were great. Yours turned out super. Just hope I don't have the motor problems after I am back together. I don't have a B. Leonard here to help out like that.

Joey:D

[B.Mac]

Let's see some pics Joey!!!
B.MAC:D

[jamoore]

Old wood gone, trial fitting first new piece!

[jamoore]

holding first piece in place while it sets.

[jamoore]

Sorry looking hand(s) (can't figure out how to take a picture of both of them). Tearing up my hands getting in those tight spots. Are we having fun yet? They really feel good when the Acetone hits them for clean up!!!!!

[tunnelmike]

When I get to a scanner I will put all my pics from the stuff repair on the board.

[jamoore]

Another update. Found time to get a little more work done on it this past weekend. Here is the second layer of plywood getting coated ready to install. I added knees to tie it into the existing knees/stringers for extra strength.

[jamoore]

here is the second layer clamped in place.

[175checkmate]

Great job so far, It is a great looking boat. When done you should have no more trouble out of the transom.

[jamoore]

Thanks for the compliment. If I do have any more problems I think I will just pull the plug on it and swim in. Then I will post a Lost Mirage story on it. Actually, just kidding, don't have a lot of $ tied up in the whole rig so I can't complain about needing to put a little time and effort into it. Should be solid when done.:D

Joey

[Reese]

are you planning to build up the transom thickness...it only looks like you have one sheet of 3/4" ply right now?

Not sure if you are planning to fiberglass the hole thing but you have a lot of 90 degree sections where the new knee brace is bonded to the old...it may be difficult to get the fiberglass to lay down with such sharp angles.

[jamoore]

Thanks Reese: There are two layers of 3/4" Marine Ply there. The most recent pictures were of the second piece going in. Already had the first in and glassed over. Becasue of the way they fit, 1st piece extends past the edges of the existing knees, I had to do them in stages verses joining them first then putting it in.

I rounded the edges over with a router to help the glass lay down. Can't really see it in the picture. May still have some difficulty getting it to lay down still. Will see this weekend when I cover it over. Also thought about mixing up a batch of thickened resin or kitty hair to help blend it in where the sharp edges are. Kind of make a little radius where they join to make the transition easier. Will post more progress shots next week.

Joey

[Reese]

Also thought about mixing up a batch of thickened resin or kitty hair to help blend it in where the sharp edges are. Kind of make a little radius where they join to make the transition easier.

Good idea...

[jamoore]

Got a little more done this weekend. Some more glassing , no need for pictures of that since it all looks the same. Did want to show a shot of this though. Picked up this tip on the board a while back. While drilling the new transom, decided to put in stainless tubing. Left it sticking out here for the picture. Will eventually glue/epoxy it into the transom. No way water can infiltrate the mounting holes now. Jack plate bolts go through the tubes. Wood is completely sealed and protected from water now. If it were to leak, it would go all the way through the transom and drip into the bilge.

Took me a while to get these done. Took the jack plate apart to use as a template (lighter, easier to handle apart) drilled holes one at a time. Positioned plate, marked and started hole, took plate off, finished drilling, finished hole to right size, put plate back and put bolt in, then moved on to next hole and repeated it again. Takes time but wanted to make sure holes were right. No room for error, also had to cut and clean up tube pieces, Each needed a little fine tuning so bolt would go in easy without damaging threads. Getting there, slow but steady

Joey:D

[beko21]

Joey, that's a great idea but are you going to open the holes in the transom to be able to get the epoxy around the tube? if so by ho much? what is the OD of the tubing you are using? I'm putting on a new jack plate and thought of doing the same thing, my bolts are 1/2" so I thought about drilling the holes in the transom out to 9/16" for the tubing but you still need room for the epoxy.

[jamoore]

Beko: Not sure what the outside diameter is. I ordered several different pieces of tubing because I was not sure what would be the best fit. Seemed like the listed inside sizes they had were either just over 1/2" or just under 1/2". Didn't know which would work best so I ordered some of each. Also they had different wall thicknesses. I just played with the samples I got to see which seemed to work best.

I can measure the outside if you need it but the inside was more critical to me. I wanted a snug fit. Didn't want the bolt to be loose in the tube. The one I used seemed to be a good snug fit. I did run a 1/2" bit through the tube to clean it up a little. Was just a hair (technical term) tight in a couple of spots.

I did have to drill larger than1/2" holes in the transom for the tubes. I forget what size I used. I just picked a bit that matched the O.D. of the tube. Used a small sandpaper roll to get it just right after drilling. I just want it loose enough so I can get a good coat of epoxy in there before I slide the tube in for good. I sealed the inside of the holes already with resin. Don't think I need a lot of play for the epoxy. Just enough to get some in there. I know others have done this because I got the idea from reading the board. I think it is the way to go to protect the wood. Looks like years of seepage around the mounting holes in the old transom is what did that one in.

Joey

[beko21]

Thanks Joey

[B.Mac]

Keep it comin'!!! Summer's upon us........You do great work!!!
B.MAC:D

[beko21]

Joey, where did you get the tubing, I've called everyone and can't find it, Kevin

[Techno]

I got that from the gougans book- west system epoxy.
They suggested it for mounting lead keels on sailing boats.

You want 2 things-
1 as rough a surface on the OD of the pipe you can make. File it, turn it, sand it. but a very definate mechanical bond. Thats why threads on it are OK. The more hashed up the better.
2 some slop in the hole. The bond is actually the filled epoxy and to do that you need room to force it in the gap. If you slather the pipe and insert it the stuff gets wiped off.
The sealing deal is to protect & seal the bare wood and the space is for shoving the filler between the tube and hole. If it's a nice tight fit you don't get a good bond. You can't postively fill the whole space.
If you don't seal the wood the filled epoxy won't penetrate the raw wood. The wood is raw still and there are gaps in the bond from the resin starved filled stuff.
You slather the pipe, insert it and then start forcing more in with a putty knife. When it comes out the other side it's filled.

I used brass nipples and drilled the tie down ones out to fit. One spun from the heat generated so they are easy to take out if you need to. You either drill them out or spin them while trying.
I ground them flush afterwards.

The theory of how this pipe thing works is the circumference of the pipe is inchs of bond. Multiplied by it's length is the square inches of bonding surface. You don't get any internal bond with a bolt.
.5" pipe 1/8" wall thickness =.75"OD
2.3" x only 2" tramsom =4.71 SQ. Inches of bond per bolt.
If you used 1/4" walls = 6.28 SQ. In. so you can see a little bit makes a big diff.

The bolts clamping force is transmitted to this area all around the bolt the whole depth of the hole so this bond is important. It doesn't seem like it but this much epoxy has a big bite on the wood. If the bolt were just bonded in would be approaching the breaking strength of the wood. They did a test on that too.
The pipes aren't just a through fitting but a transfer of loading internaly to the transom. Something like a backing plate but better.

One of the booklets showed them testing bolts for a boat. The builder wanted to know how thick the wood needed to be for a bonded in bolt. They tested from wood failure to bolt failure, the bolt broke not the wood!. Told the guy the right thickness of wood since anymore was a waste. A certain thickness got them the strength and more wasn't too much an increase.
They need to put this kind of stuff on their website.

If you can't find something try http://www.mcmaster.com/ Its a bit of a pain searching without a book but they'll have it. You'll get it in 1-3 days after ordering too.

[beko21]

Techno, thanks for the info, I found some stainless pipe at a local iron yard after I had called all over Ohio, Penn. NY, I found it here in town, always the last place you look, it has a OD of 7/8" so the wall thickness is 1/4" BUT the ID is .057, it doesn't have a lot of slope but it's not a tight fit either, do you think this will create a problem?what kid of torque should I put on these bolts? I don't want the 300 to end up at the bottom of the Ohio river,Thanks for your input, Kevin

[Reese]

idea on the transom pipe...but was too lazy to find stainless steel.

Home Depot sells a small 6" x 1/2" copper tube that is used to keep your water pipes from rattling...don't know what it's called but it's got a heavy wall thickness and is good choice for 1/2" bolts.

I think Home Depot is sponsoring my boat project...:)

[sho305]

I did mine before he posted that, so I drilled big and mixed some little glass fibers in resin and painted in the holes a couple times. Drilled the right size and used big washers on my little motor. Then lots of 5200 wonder goop. Hope it comes off if need be because I glued the whole clamp on.:eek:

[Techno]

Not my idea I just repeated what the googy bos said.

I wouldn't use copper, just feel it's too soft. If they have copper they should have brass or bronze-same thing.
what I try for is to have the pipe flush both sides. The bolt tightens on the pipe and stops. Tightening on wood you can keep going untill you here it crack or something. The flush thing is to let you tighten to the wood transom too. If the stress is on both I don't see how the pipe can move. It' bonded internaly and spreading load there. The bolt is flush on the wood and is spreading load there too.

The ID of the pipe don't really matter a whole lot. It needs a bit more goo to seal the bolt so it don't leak and I assume too much slop would put the bolt under a side stress. like a 3/4" ID for a 1/2" bolt.

The sloppy fit is the OD of the pipe so you can get some spooge pushing room.
The torque would probably be what ever the standard is for 1/2" bolts, I would guess this is more than you get with just the wood squeeze normally.

A torqeing note. This is to stress the bolt a specific amount. Any more is borrowing from the bolts strength. If this was 60 KPSi and you torqued to 20 KPSI you still have 40. If you gorilla it on and achieve 50 KPSI of torque this leaves the bolts strength down to 10 KPSI. If the load is like 9 or 11 guess what happens. #s just for example.
Torque is the indirect method of bolt stretch. It's bolt stretch you want but is usually too difficult to do.

[jamoore]

I have been away and missed your question. I think Techno answered all the questions. I am too stupid to understand all of it though but I can grasp the concept. I probably got the idea from one of his posts originally.

FYI, in case anybody else is looking, I orderd my tube on line from online metals. I ordered several pieces of different i.d and wall thickness to see which one worked best. My memory is that they had i.d. 's of either just over or just under 1/2". Different wall thicknesses as well. I just played around and found the one that gave me the best fit for the 1/2" bolts. Mine is a pretty snug fit through the tube. I don't think you want a lot of play here. Not sure which size I ended up using. They were not marked as to which was which and I didn't bother to measure or try and figure out which one it was. Ended up with the thicker wall size. Still plugging away on my transom as time permits. Getting closer!!

Joey

[B.Mac]

Let's see 'yer progress.....
Get back on that transom!! Where's 'yer priorities? Whata' ya doin'? Workin' on the house?:D ;)
B.MAC:D

[jamoore]

I don't know where the time goes. I have been working on the Mirage when time permits. Also working on my other boat trying to get one of them into the water. Can't believe it is July 7 and still nothing wet. Of course we had such a cool and wet spring/summer up until a week or so ago seemed like summer wasn't coming at all this year.

I finished the transom, went ahead and glassed in a piece of plywood inside the rear of the sponson to mount a speedo pick-up to while I had it cut apart. Couldn't reach it with the deck on. Had a speedo in the dash but never mounted the pick-up. Could tell there was nothing but a couple layers of glass back there. Was afraid it would pull right out. Now it has something to hold it.

Will post a couple of pictures this week. Getting ready to start glassing the deck back on. Want to make sure there is nothing else I want to do while it is off before I seal it up. Last chance cause I don't want to cut it up again.

Of course ten thousand other house,yard, misc, projects all requiring time as well. Oh well, gives you a reason for living. Wouldn't know what to do if I ever got caught up. Yes I do, get more projects.:D :D :D

Joey

[sho305]

What is with this place...Jamoore-"ten thousand projects....will get more projects..."


Stop describing me!:D :D :D

[beko21]

Jay, I've got a trailer that needs to be painted if you don't have enough stuff to do (lol) I started this project of mine to put a alien cowl on a 260 motor and ended up putting the 300x on and carpet and gauges and... well you see what I mean, Kevin

[jamoore]

I think I may get the world's record for slowest progress. Slowly but surely it is coming along. Here are the latest shots.

New transom in almost ready to start putting the top on.

[jamoore]

Closer

[jamoore]

rub rail going back on

[Reese]

I think I may get the world's record for slowest progress.

You have a long ways to go before you win that award.

Hey I'm getting all geeked out cause I get to prime and paint the interior this weekend...and I'm comming up on year two...:(

[B.Mac]

Startin ta look like a transom again!!!
GET BACK TO WORK!!!
B.MAC:D

[Talon2.5]

looking good!!

i dread the day i gotta do this!! :(

[jamoore]

Still at it. Some more progress pictures. Lid is in place ready to be glassed back in.

[jamoore]

ready to start glassing!

[jamoore]

Starting to blend it in

[jamoore]

Almost there, primer at last.

[Donnie]

I have a hull just like yours and I was told it was a myak hull you did a killer job on the transom leave your # if you have ever heard of this kind of hull Thanks Donnie. My # 814 244 8830

[jamoore]

Hey Donnie: I think this is a Mirage. It was sold to me as one but the guy who sold it to me was very intoxicated and I don't think he owned it long. Never got a title from him and have no idea what year it is. Once I got working on it (the first time), I stripped off two old paint jobs down to bare gelcoat. I could see the outline of where it had MIRAGE written down the nose. I never found any hull i.d number on the boat. After reading all the posts about copies I am not sure what this one really is. Never heard of your boat before. Must be one of the many splashes that were apparently made of these hulls.

I am almost back together now. Sprayed the blue and clear this weekned and started rigging it again. Should have it back together and running this next weekend. Just in time for summer? well in time for fall anyway.

Joey

[jamoore]

Finally done: Here is the before picture.

[jamoore]

voila!

[thaw ripper]

Damn looks like all the hard work payed off in the end. Very :cool::cool: :cool: :cool: :cool:

[sho305]

Nice work!

[k-man]

exellent - let use know how it runs ;)

[Donnie]

ja what oz. fiberglass mat did you use if my boat don't sell I'm going to do the transom on that myact I was telling you about if you could call me and give some advice.. my # 814-322-8956 Thanks Donnie