1995 Crownline 202BR Restore

MikeSchinlaub said:

I recently did a transom job with a clearence issue like that. My supervisor has an extended shaft straight die grinder that helped a lot, along with a few carbide bits and a stone ball. Later, I had closed the gap even more with glass, and had to come up with something else. I taped a stir stick to a sawzall blade, and cut a piece of psa 36 grit sand paper to fit it. It was a bit slow, but worked well. Longer blades will let you put some pressure on and flex them.

As for the sidewalls, just gel would probably be best. If you use the foam, could you set up a blower on a timer somehow to dry it out? Even just a tiny box fan left in overnight would work.

Click to expand...

The die grinder worked pretty well. Thanks for the tip.

After some summer getaway time, I'm back at it. Made my fiberglass order from US Composite and found a local source with marine plywood. It's nice to be able to by it in by the sheet as I need it and not have to store extra as I really don't have room. Others have mentioned it before but USC can ship to a transit terminal and you don't have to pay the hazmat charge on the resin. Shipping was half of what it would be if I had it delivered to my house. Well worth the 15min drive to pick it up.

Going to get to work on the transom today. Hopefully get it cut out and the glue up started.

Got the transom cut out and glued using Titebond III. Based on the keyhole cutout, everything looks good. Did a dry fit and all looks good. Going to route out the extra space for the steering linkage at the top of the keyhole next. Hoping my USC order arrives by Friday so I can start the glassing this weekend.

Question about mixing resin... I understand the glassing process to be

1. soak the wood surface with resin until it stops absorbing it
2. let the resin on the wood surface get tacky
3. apply the CSM or 1708 to the wood
4. wet out the CSM or 1708
5. repeat steps 3 & 4 as necessary to build layers

Can I do all of this in one batch of resin, or will it take long enough such the resin in the container will begin to harden and not be usable? In other words, do I need to make multiple, small batches of resin or can I mix enough for this whole process at once? At first, I'm going to be doing some small pieces (12" x 18") with only 1 layer of CSM but then will come the transom. I'm guessing the answer is different depending on the size of the area being covered and the number of layers needed.

I assume this is all about getting the transom in, so here is what I recommend.

1. Attach transom to hull with thickened resin.
1a. Spread thickened resin across the back of the transom at least 1/2 inch thick, you can avoid the I/O cutout.
1b. Lag or clamp transom in place and leave overnight. You want resin to ooze out all around the edge of the transom. Use a bondo spreader to smooth it all out, and fill any gaps. You want to have a smooth transition from wood edge to hull glass.

2. Next day, use a grinder to scuff up all of that resin. Leave as smooth of a surface as you can.

3. Gather all of your glassing materials. You want two layers of csm and one 1708 across the whole transom, and at least six inches past all the way around. Cut the 1708 just a bit shorter, so it doesn't hang past the cam. Fill any low spots with more csm.

4. Start glassing. I can do a quart cup of resin at a time, but depending on your speed and temp, you might start with half. Do the 2 mat, roll out all of the air bubbles, 1708, roll it.

There's no down time once you start, you're racing the clock trying to get done before the resin sets up.

This might help.

Did some experimenting with the resin and CSM to get a sense of the timing on the application. It's 70-75 degrees and I'm getting about 30min until tacky and about 1.5 hours until the leftover resin starts congealing in the container. My math was off on my initial measuring of the MEKP and it hardened up like a brick in about 30min. That was a duh moment once I figured out my math was off. Applied CSM to a few smaller pieces as test cases. The marine plywood doesn't absorb much resin. I also learned that corners are a nightmare. I added a 1/4" radius to the edges of a rectangular piece. The CSM wrapped nicely around that but haven't figure out a great way to do the corners. I probably need to round them off as well.

After the experiments, I started on the transom. Got the backside covered with CSM. I did it in 3 pieces, one the main section in the middle, then both wings. It was much easier than trying to get that odd shape all in one try. The CSM wrapped nicely around the edges. It's drying right now but initial inspection looked good on air bubbles.



Looking a WOGs guide and some of the other restores, it seems the CSM on the inside isn't necessary and using 2 layers of 1708 will work as the underside of the 1708 is CSM. Looking at @Rickmerrill restore on a nearly identical boat ('94 Crownline 182), he tabbed in the transom with 1708 then did 2 layers of 1708 across the inside. Seems like an easier route. Is there a downside to this approach?

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I always forget what the numbers correlate too. At work, 1708 is "byply", and the woven cloth is roving. Just what I learned with. So what I meant was 2 layers of csm and one roving.

Yeah, fiberglass hates corners. Round them well, and finish by hand with some 80 grit. It will get any left over points from trying to round with something like a grinder.

For outside corners, I find it helps to tear the csm and do a layer where the frayed edges are just going around it. You can also just shread it by hand. The looser the fibers, the easier it will wrap around. Same for inside corners.

3 point corners, you need to tear the glass so it isn't trying to fold. Using the shreds here is also a big help.

Also, if you're wetting the glass on a board, and transferring to the surface, use your fingers to scrape up all of the strands that stayed behind. Those are great for filling difficult areas.

Make sure you scuff that glass well before you try ro bond it to the hull.

Whenever you are going to be using resin on wood, make sure to smooth out the left over splinters from cutting it. If you leave them and resin them, each one becomes a little razor blade. Might not be relevant now, but good to know.

Transom is installed! Biggest issue I had was not making enough PB. I made 4 quarts to start with. Ended up using 7 which created a bit of a time crunch at the end. My fillets were rushed so they'll need some cleanup.

My PB receipt was equal parts resin & carbosil, with 1/4 cup chopped strand per quart. I backed off the MEKP by ~30% to give me more time which I definitely needed to make the extra batches.

Couple lessons learned...
1) My bottom clamp on the inside is too low and interfered with my ability to get a good fillet. I should have cut more off the tapered end to give more space.
2) I should have put all 4 clamps on hand snug, then slowly tighten them together (i.e. turn the nut on each clamp one turn, then move the next). I think this would have allowed me to get a very uniform thickness around the keyhole. I'm not way off now (0.1" variance) but I can expect I'll have to do some leveling out once the inside is glassed.
3) Make way more PB than you ever expect to use!

Nice. Don't worry about the bottom, just scuff it up and glass over.

It's a bit late now, but you should have cut the bottom out so the drain hole won't have any wood around it. My fault, I forgot until I saw it in. You could go ahead and cut it out with a hole saw, maybe router the wood out a bit bigger, and fill it in with putty. This way, if it does leak around the drain a bit, it's not contacting the wood.