"glue and screw" question

[WillyC]

I have a 20' sf and I'm about ready to install the new transom core material (coosa board). This job will be done from the inside and I will be using the "glue and screw" method. My question is, do I need to use some type of releasing agent on the thru bolts so they are not epoxied in place. I remember reading something about this a while back but cant find the post now. Any other suggestions would also be great. Thanks -Will

[oldbluesplayer]

Will - from my experience, you absolutely must use some way to keep from epoxying the bolts in place.

Also, are you planning to use any means to spread the bolt tension force out over a larger area ?

If you read thru my thread, you will see I used pieces of 2x4 on the bolts to spread the bolt loads out across the transom as it cured - other readers contributed their methods inside that same thread.

I chose not to use any release agent, for fear of it soaking into the wood, contaminating it, and preventing good adhesion when I plugged the holes later on.

what I did was to wrap the bolts in tin foil. I drilled my thru bolt holes at 3/8", used 5/16" carriage bolts, because they are threaded full shank, wrapped in tin foil, and didn't worry if the squeeze out epoxy grabbed the tin foil - after that segment was cured, I re-drilled the hole back to 3/8" in preparation for the next layer, cleaning out any residual tin foil.

At the end, I drill / cleaned the holes, taped off on one side, flush, and taped a dam on the other side, and filled with a thickened epoxy mixture.

hope that helps some

Bill

[WillyC]

Bill,
I do plan on using 2x4's and other pieces of wood to distribute the bolt tension. The aluminium foil sounds like it worked and I'll use that if there's not some kind of wax that can be applied to the bolts. Thanks -Will

[stoney]

I used Coosa board and stiffened the glue job with a tee made out of 2 x 6's while is set to keep the transom flat. I used through bolts wherever there was an existing hole ( there were 52 holes in the transom). The bolts came out no problem. Be sure to keep the transom flat and check before dimensions on the transom so the deck cap fits back on.
I posted pictures on another transom job rebuilt post. Finished the job in July and I am very happy with the result with Coosa board, epoxy and biaxial cloth.

[WillyC]

Stoney,
Can you be a little more specific about how you made the tee out of 2x6's. Also did you use any releasing agent on the through bolts. I will be using the same materials as you, coosa board, epoxy and biaxial cloth. I also checked out two pictures that you posted and it looks like you have a 23' sf. Do you thik the transom on the 20' needs additional structure or support aside form the original setup? Thanks -Will

[Scott]

From another thread
Stoneys transom

[stoney]

I made the tee piece by using 3" deck screws 6" apart, screwing the two 2 x 6's into a tee. It was soo stiff it pulled the transom flat. My boat is a 71 and the transom and artful aluminum work had deformed the transom to less than flat. The original transom under the rotten plywood was only gelcoat and 2 layers of mat 3/4oz mat as best I could determine. I put a layer of biaxial on the transom and let it harden before I glued on the Coosa. I also borrowed 8 deep c clamps from a neighbor to clamp the coosa to the hull. You don't want air gaps there. You will loose a lot of strength if the board is not glued to the hull. I made a thickened paste of SLOW set epoxy notch troweled on the transom and Coosa. Put the board in and bolt and clamp as many places as you can. I used 4" square backer washers on the outside of the hull to keep from having the bolts pull a dimple. Borrow as many deep c clamps as you can from a cabinet maker. They will reduce the number of holes you have to drill in the transom. Drilling holes to clamp the transom bugged me but I was determined to get the Coosa tight to th transom. I then put three layers of biaxial over the Coosa. I then put in three knee's from the hull to the transom. They are on a 45 from just under the motor well to the hull. Did I mention I removed the livewell? The original live well was used to stiffen the transom. Without the livewell you need stiffeners in my opinion. Be sure to get a 1/2" radius router bit to round off the corners of the Coosa. It makes the biaxial lay nice. The attached shows the inside during construction.
http://i15.photobucket.com/albums/a3...epairs5_14.jpg

[WillyC]

Thanks for the advice Stoney. Your picture and the one Scott posted of your boat are great. I plan on doing almost exactly the same thing as you. I have already laid a layer of 1708 biaxial on the inside skin of the transom including strips in the corners (sides and bottom). Maybe this weekend, if Rita doesn't reek havoc over here I can get the coosa bonded in. Its not that important at this stage but im still wondering if the 20 footers need any additional transom support such as knees. Thanks -Will

[stoney]

To answer your other question I used 3/8" plated allthread. I double nutted one side. After the big glue event with SLOW set epoxy the allthreads backed out no problem. I put an allthread everywhere there was a hole in the transom, like drain plug motor mount holes, drain holes etc. I will defer to others who know more about repairs and 20 foot seacrafts, BUT the knees weigh almost nothing. There are lots of other posts of people rebuilding the transom and putting them in. The point of all this work is to make the boat better and NEVER have to do it again. If you put the knees in drill through holes for drainage BEFORE installation.

[alarie]

As to the bolt/glue question, just put wax on them before you laminate, and they will back right out. I have never had a problem with this method. If you are nervous about the wax, use McLube (available at West Marine) which is a dry film lube. Coat the screws, let dry for a few minutes, and then let the glue fly.

I have used both methods with great success.

Peter