Rotten Doghouse Repair

[jlogger]

Rotten Doghouse Repair

The engine doghouse on my Thompson is completely rotted. I can push a metal rod down through the full length of the plywood like it is butter. Aside from just hogging out the rotten plywood and fitting another piece of plywood to be pushed down inside the fiberglass shell, is there anything I should know regarding adhesives, epoxies, sealants etc? What is the most effective way to repair?  Thanks.

[Bozeman Bob]

Marine plywood or similar wood. I would put the top piece in first and then butt the three side sections against the top so they act  as a support. Might even put some 2x2 [ or smaller] on the sides up against the top piece for further support. You could get a two part resin and coat all the wood to prevent rot and even glass in the sections that butt against each other. If doing that you could use a A/B or A/C sheet of plywood. I am going to guess at this point its a working boat and its more about functionality not looks. So on that note I would nut and bolt the wood to the doghouse using a flat headed SSteel tapered Phillips head bolt and put a cupped washer under it to keep thing from hanging up on the heads and give it a flush look.. Use 3m4200 for caulking the bolts holes. Then maybe get some sound deadener and glue or screw it with oversized fender washers to the wood. Never had to do this, but that's how I would go about it..

Edited March 1, 2017 by Bozeman Bob

[rolmops]

Marine plywood is nice and expensive. In this case any bcx plywood will do. The B and the C are the quality level of finish on each side and the X stands for exterior. That means that the glue that is used to glue the plies together is water proof so the plies do not come apart. If you paint the boards and the edges with a good oil based base a couple of times and then finish it off with rustoleum oil based paint in order to seal it you should be ok. The side that you want to go against the shell surface should not be painted. Instead you must paint it with fiberglass resin (with hardener) and also put some resin onto the fiber glass itself. You can bolt it in as well.The resin will penetrate into the wood and act as a glue between wood and fiberglass. If you do it that way,you will not have to deal with vibration noise.

[jlogger]

Thanks to both you guys. Sounds about like I expected/hoped. Now I have something to do this weekend. Four weeks to splash!

[Xxx]

Yep I did exactly like Rolmops I just framed a square box with Sheetrock screws then cut that silver sided 1/2" insulation glued and stapled the pieces on the inside.  Then I used outdoor deck stain, put 3 coats on. One thing to do is put an edge around the top. That way you won't be picking up everything you lay on the top off the floor. I just put a 1/2X1/2 inch border around the box including against the back. That acts like my stop, used the same floor latches. Finally I drilled holes ever few feet for the water to run out, used 3/16" bit I even sloped the front back to add a little bit of looks.