Doghouse reconstruction

[ScottinAZ]

I am at the point of my rebuild where I need to remake a doghouse cover for the engine.

Originally the doghouse was just plywood, fiberglass and some sprayed in foam for noise abatement. Personally I feel this is inadequate and a fire hazard.

I am considering building a frame out of angle iron that I can screw the plywood (either fiberglassed or polyurethaned for water resistance) outer cover to, and then use some automotive style underhood insulation for the inner, rather than the sprayed in foam that is a known fire hazard.

What is the standard way that others here have redone their doghouses, and am I overthinking this?

 

[matt167]

If you want to use a metal frame, use aluminum. Dynamat would be okay to use

 

[Chris1956]

A metal frame is not necessary, and can get heavy real fast. Also, a lot of doghouses have non-90* angles, which will be difficult with angle iron.

1/2" plywood is fine. I recommend you dry some pressure treated CDX for this job. Stick it in the rafters of the garage for a couple of weeks.

For the plywood to plywood joints with angles, use some fiberglass cloth tape + polyester resin over the joints for strength, inside and outside. For the rear of the top plywood piece, use a 2X2 inside the doghouse to reinforce the top edge. Seal everything with poly resin or a couple of coats of spar urethane. Use stainless screws for the 2X2.

Cover the outside with some matching vinyl, and the auto foam on the inside is ideal. I also used a piece of outdoor carpet for the top of the doghouse, for a more durable surface. A thin plastic cutting board would also be good.

 

[Baylinerchuck]

If you are going to use fiberglass at all, I would stay away from treated plywood. If you’re going to vinyl wrap the plywood, treated is fine. All of my vinyl wrapped backers were treated to a generous drink of old timers wood sealer. 2 parts mineral spirits, 1 part linseed oil, 1 part spars urethane.

 

[ScottinAZ]

A metal frame is not necessary, and can get heavy real fast. Also, a lot of doghouses have non-90* angles, which will be difficult with angle iron.

1/2" plywood is fine. I recommend you dry some pressure treated CDX for this job. Stick it in the rafters of the garage for a couple of weeks.

For the plywood to plywood joints with angles, use some fiberglass cloth tape + polyester resin over the joints for strength, inside and outside. For the rear of the top plywood piece, use a 2X2 inside the doghouse to reinforce the top edge. Seal everything with poly resin or a couple of coats of spar urethane. Use stainless screws for the 2X2.

Cover the outside with some matching vinyl, and the auto foam on the inside is ideal. I also used a piece of outdoor carpet for the top of the doghouse, for a more durable surface. A thin plastic cutting board would also be good.

the shitty original doghouse was mostly a square box, with an overhang on the back, so the new one will mostly follow this pattern. It was 1/2 ply with a **** poor almost coating of CSM on the inside to hold it together (barely). Outside was another skimcoat layer of csm and resin that peeled right off. I was thinking to poly the wood after screwing it to the thin gauge angle stock (probably steel, as I can weld that into shape) and then generic underhood foam on the inside. In reality, its overkill, but it would make it easier to replace a piece of the ply when it gets crusty (which it eventually will). Not too worried about weight, thin gauge 1" angle stock shouldnt weigh more than about 20-30# for the amount I need, and then to offset, I COULD (but not necissarily will) go with 3/8 or 1/4 inch ply. Its just a cover afterall, and any idiot that sits on it deserves to go through it . normal payload for the boat will be just myself, wife and our son, with MAYBE one other on occasion, so we have some room to play with things a bit. outer finish will either be vinyl or marine carpet, that is yet to be determined.

 

[airshot]

My doghouse was made of 5/8" plywood with 2x2 lumber on inside corners to screw into. This thing was strong as an ox, two grown adults could stand on it and dance if they wanted. No glass work, covered in marine carpet. Sold the boat after 12 plus years with the doghouse strong as ever.

 

[Scott Danforth]

My doghouse is all fiberglass with a bit of balsa coring in the back.

If I were to fabricate one, I would make a plug out of PVC sheet, then cover with core board, then cover in 2 layers of 1708 fiberglass. Once cured, I would remove the PVC and cover the inside with 2 layers of 1708

 

[ScottinAZ]

A metal frame is not necessary, and can get heavy real fast. Also, a lot of doghouses have non-90* angles, which will be difficult with angle iron.

1/2" plywood is fine. I recommend you dry some pressure treated CDX for this job. Stick it in the rafters of the garage for a couple of weeks.

For the plywood to plywood joints with angles, use some fiberglass cloth tape + polyester resin over the joints for strength, inside and outside. For the rear of the top plywood piece, use a 2X2 inside the doghouse to reinforce the top edge. Seal everything with poly resin or a couple of coats of spar urethane. Use stainless screws for the 2X2.

Cover the outside with some matching vinyl, and the auto foam on the inside is ideal. I also used a piece of outdoor carpet for the top of the doghouse, for a more durable surface. A thin plastic cutting board would also be good.

well, its been a while, but I finally did the doghouse this past week. Did almost exactly as Chris stated, save for doing the fiberglassing. Instead for strength, I used aluminum angle brackets in all the corners (modified to fit any odd angles I created when I leaned the front back) and covered it with 1/4 foam backed vinyl, and marine carpet. I have the insulation for the inside on order, it just hasnt arrived yet. For the exterior edge capping, I have some aluminum channel that will cover the edges of the carpet and vinyl, and keep them from peeling back. The body is glued, but who knows how that will stand up over time. The aluminum channel is a good safety net.

pardon the carpet on the deck, I havent yet glued that down. Its just sitting there to make it look like I did some actual work.....