bonding transom

[PiratePast40]

Re: bonding transom

You've got several questions going on and people have different opinions. I did like most people and laminated with CSM and resin. I used screws to hold 2 pieces together until they cured. I then removed the screws and added the third layer of ply the same as the first. After each layer, I also did the best I could to make sure the voids left by the screws were filed with resin. I think that part is pretty common. I happened to use PL premium as bedding since it's relatively dense, dries hard, and is adhesive. Some people prefer a resin mix with filler (cabisol, resin and other filers to make peanut butter). I will caution you about any thick adhesive - it may be much thicker than you imagined - somewhat like taffy. Either buy a high quality, ratcheting calk gun or be prepared to cut open the tube and use a putty knife to spread it. I wouldn't mix resin for placing the transom until the bedding is in place since it may take longer than expected.

I rough cut the transon plate hole and then precut and driled 2 x 4's and other pieces of lumber to use as clamps. here's some pictures:

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I'm certainly not the first to do it this way and other people have some techniques that are just as effective. Just hoping to throw out some detailed steps and hope they help.

 

[66mstgfsbk]

Re: bonding transom

piratepast40,
when you mentioned bedding the transom with pl did you lay the pl on the hull where the bottom edge of the plywood goes, and if so how thick did you lay the bead? im kinda lost sorry. thanks for the help

 

[PiratePast40]

Re: bonding transom

I had the new transom in and out of the boat many, many times to make sure it fit right. I started with making a cardboard template and then just kept fitting and trimming to make sure it was right. From repeated test fits, I was able to determine where the gaps would be. When it came time for actual bedding in and installation, I gave everything one last vacuum, wet wash, and aceton rinse. Then I laid down a thick and wide layer for the bottom of the transom. I then mixed up the resin and coated the new transom and the boat transom. Then the tramsom was put into position and clamped and screwed.

I went back later and filled in the remaining gaps with PL. In some cases, it was getting a little thick so I let it begin to cure before adding another layer and making the transition smooth.

I let everything set for a couple of days and then went back in to begin the process of tabbing the transom to the sides and bottom of the hull.

I know that sounds a little long winded but wanted to give you a good sequence of events. I find it easier for my barnacled brain to understand and plan if I have the story in my head first.

Edit: Another issue with the resin. I liberally coated the outside of the hull with paste wax. Resin that oozes out from the bonding and clamping is a little easier to remove if it doesn't try to bond to the existing glass/gelcoat. The wax makes it harder to stick and thus easier to remove.

 

[66mstgfsbk]

Re: bonding transom

i finally got the transom in bedded and bonded. few more questions, there is a few spots that did not push up flat against the wood and the original structure i used wood to pull it snug but it didnt help in that spot. there is a gap about 3 mm, can i get a turkey baster and squirt resin with chopped stands to fill this gap? also i need to plug a hole so resin doesnt pour out if i can baste it in what can i use? foil type duct tape, masking tape, scotch tape? thanks for the help

 

[66mstgfsbk]

Re: bonding transom

bump

 

[jonesg]

Re: bonding transom

Duct tape will form a dam but will not hold back a flood, it depends how much resin (weight) will be going in there.

You may want to do it in 2 batches, let the first batch seal the bottom area then fill the rest with a fresh resin mix, I do like everyone and add cabosil with some chopped fiber, bang the transom with a rubber mallet or 2x4 to keep it flowing as you inject it. Depending on the situation, it might make sense to drill a hole to inject filler resin.