1978 Viking rebuild

[tnelsmn]

Thats some great looking work there Twisted!

A few updates since the last post. The bow eye block is glassed in, I still need to add some 1708 over it, the plug block has been bedded in. I used two layers of 3/4" plywood glassed together for the block. Also have the front bulkhead bedded in. I rough cut the floor to start fitting it to the hull. Kinda wanted to see how it looked with a floor agin, kinda felt like a mini milestone. I'll be adding a stainless steel plate to the underside of the floor for reinforcement for a tow bar. The boat will see a fair amount of ski boat duty.

I'm now leaning towards adding drains anywhere water could sit. So the next question is, would it be worthwhile to cover the glass work below the floor with a layer of gel coat before setting the floor. I wouldn't coat the top of the stringers or the strake where the floor would bond. Am I overthinking this? Thoughts? Thanks!

[XstreamVking]

Wouldn't hurt a thing...I flow coated my lower bilge area. I also have several holes fwd to allow air flow thru the sub floor. Bilge aft is open where the pump sits for air flow. (not boxed in) My sub floor stays powder dry.

[LakeFever]

My thinking is coat anything and everything you possibly can to avoid water issues. Most of the $ in these mods are time heavy and very little extra cost on materials. Plus when we restore things to keep its a very different approach than building to sell and how many builds like this are you goin to have time for in life? Go full effort on protection and quality best you can as it already looks as though you are.

Great build

[Hippie459MN]

Mine has gel coat over everything under the floor. Wouldnt hurt.

[tnelsmn]

Still slowly picking away at it over summer. All under floor structure is complete.

The front stringer was made from 1/2" marine ply. Looking back I should've just made all my stringers out of 1/2" instead of laminating two pieces of 1/4", would've saved me a ton of time, probably a little weight, and without giving up much strength.

As I did with the other stringers I laid a 4" strip of 1708 on top of the core where the stringer and bulkhead would sit. Same as before I used the M-1 marine adhesive to bond the stringers to the core then mixed up some putty to set the radius. Tabbed in with 1" of CSM followed by 4" of 1708 and finished off with two full layers of CSM.

Finished off the bow eye with two layers of 1708 and finished off the plug block with three layers of CSM. I added some putty to the outsides of the knees so any water that might get in there will drain into the bilge in front of the plug.

Currently working on giving everything a good sanding below the floor level to remove any excess resin drips etc. to prepare for gel coat. I drilled all my drainage holes through the stringers and bulkhead. I'm planning to coat the inside of the drain holes with resin and give everything a light brush coat of resin before gel coat.

[LakeFever]

Lookin amazing! I wish I could have a few of you fellas over for one week this winter and smash out my resto at this level, even though its decent its not this quality which is what I want. You must be thrilled with the results thus far

[tnelsmn]

Lookin amazing! I wish I could have a few of you fellas over for one week this winter and smash out my resto at this level, even though its decent its not this quality which is what I want. You must be thrilled with the results thus far

Thanks! I'm really happy with the progress so far. It's taking longer that originally anticipated, but oh well it's a fun process. Don't underestimate yourself. This is the first time I've done fiberglass work. Patience is key.

[XstreamVking]

Looking spiffy.. I wouldn't waste time resin coating before gell. After all gell is resin too.....It will bond better if you wipe it down with styrene or acetone and then gell it. Use some wax in the gell if it's not pre waxed to seal the surface.

[DanUmbarger]

Your doing a great job....top notch. I just can't wrap my head around using marine adhesive under the stringer,radiusing it with your finger then glassing over that radius. First off I don't believe the glass will stick to the adhesive then your bond to the hull will be 1/2" away from the wood. I was always taught that running the glass all the way to the wood would give you a 90 degree edge at the bottom of the wood giving you adhesion right at the wood and also give you added strength of the glass plus the wood. Maybe I'm all wet....someone straighten me out? Otherwise it looks great!!

[tnelsmn]

Xstream, thanks for the tip! I was curious whether or not I could skip the finial resin layer. Looks like I'll have it in gel sooner than I thought. I did pick up the wax additive to go with the gel. I've been doing an acetone wipe down on everything so far before any glass work.

Dan, you bring up a good point, I hadn't thought of that before. I suppose I should've done some testing first. Sadly I'm a bit beyond changing my method at this point, but I'll still make up some test pieces out of curiosity to see how well glass sticks to the adhesive. I remember hearing/seeing somewhere that running a radius on the fillet was how to do it. Gives the mat a a smooth transition instead of a sharp corner that could be a stress point. I could've got bad info, I really don't know. Here is an info page to the adhesive used if you're curious.
https://www.chemlink.com/Products/Sp...263-M-1-Marine

[XstreamVking]

Looks similar to a 52/4200 caulk. If it's well cured should not be a problem to glass over.

[LakeFever]

I saw a bunch of pics from a John Spaeth resto and he did the same thing except the silicone type product appeared to be green but he laid the stringers over the sealer same as here

As for the resto work I know I can do it but I don’t know if I have the time. That’s my issue more than anything for the foreseeable at least

[tnelsmn]

I saw a bunch of pics from a John Spaeth resto and he did the same thing except the silicone type product appeared to be green but he laid the stringers over the sealer same as here

As for the resto work I know I can do it but I don’t know if I have the time. That’s my issue more than anything for the foreseeable at least

That I can understand. I've got about 280 hours into it so far, mostly in 1-3 hour work sessions. Having space to do it is a huge plus too.

[GregAdams]

You know that guy that is always getting a bit of water in his buoyancy tanks but he has checked the hull and it is good, and he has checked and resealed the bung fitting and it is good. His underfloor compartments are probably airtight. i.e. There aren't any breathers in the floor.
If you make the under floor compartments air-tight, then they are subject to air pressure changes with changes in temperature. This becomes apparent when you put the bung in the transom on a hot day and then put your boat in the cold water. The air inside the sealed hull compartment is cooled by the water outside the hull and the air contracts creating a small vacuum inside. One of two things happens. It sucks water in past the o-ring on that troublesome bung (the mysterious leak). Or it doesn't, and then you go out wave jumping in the rough water with the hull panels already pre-stressed by the vacuum inside. Only takes a small pressure differential over a large area to create significant deformation. And then the slamming loads deform the hull panels even more. You see it when you pump up an inflatable boat. The tubes are hard before it goes in the water. When you put it in the water they gradually go soft as the air inside cools and contracts.
The solution is to place a very small breather hole in the floor. Don't put a breather hole in your inflatable boat … lol
Another example:- Have you ever popped an inspection port while slamming in rough water? These things aren't really a problem if you have an overbuilt slow fishing boat, except for the inconvenient leak. But the leak slows down after the pressure differential is reduced by the volume of the incoming water.

So here's a question for the group. I've had a few friends raise the question of adding drain holes in the bottom of the forward bulkhead(front edge of main floor) to allow for drainage. Also a corresponding hole in the piece I'm adding between the stringers to establish the front wall of the bilge.

I haven't been planning to do this. My thought was that it will all be completely sealed and no water can enter, so no need to drain it. I will be gel coating the entire inside of the hull once wood work is complete. So any water would need to penetrate gel coat, then the resin and glass.

Friends argue that water will make its way in there somehow. It is a boat after all haha. So it needs a way out.

After thinking about it some I started to consider condensation forming below the floor and not having a way out.
Should I add some drains in the bulkheads, possibly drill a drain through the stringers near the bilge area, cut a vent under each seat box?

Thoughts, past practice? I would like some advice from people who've done this before. Thanks!

[tnelsmn]

Greg, that's a great explanation. I have added drain holes to my stringers and bulkhead. I'm planning a vent in very front of the forward floor/shelf and possibly adding a vent below either seat. I believe this would allow for plenty of airflow below the floor combined with the added drain holes.