Build doghouse over engine

3/4" Airex rigid foam I believe is distributed by Baltek, an Alcan company (I get a lot of balsa from Baltek and they are very helpful if you want to call and ask questions). The foam will route neat as can be but you must wear lung protection. I didn't look where you are from but someone there sells Systems Three or West Systems epoxy. Systems Three gives free "how to" books on epoxy.
BTI is for "Brunswick Technologies", the people who build sporting equipment and Bayliners.They developed a material that combines mat and unidirectional fibers and is wonderful to work with if you take your time, read, cut material with a fabric cutter on a flat surface, wet out material on a piece of cardboard, wear hand, eye and lung protection. It has revolutionized lay-up and projects like what you are doing. There are many companies producing it now and comes under many names - ask for "combination cloth" and most boat places will help. One layer of 17oz stuff will be hell-for-stout. Two would be bullet-proof. You might find 24 or 32 oz material but for you doing this, I'd stick with no more than 24. Putty can be hand mixed but better to just buy epoxy fairing putty for your project. The reason you route the corners (1/2", or more, quarter round) is so the glass will make the radius without forming a line bubble and it will look very nice. Make the box like this and the fat lady can't break it trying... Don't hurry, don't short-cut and it will end up cheap, strong, good looking, light and increase the value of your boat. Also, you don't even have to measure anything - just start gluin' and trim off after. Liquid nails sound insulation made for this with no gaps on the inside and you'll love the finished product. Good luck

 

Oh, and don't use just any foam. There are reasons I won't go into now but don't try to save money or time on the foam. Somebody near you has some. I saw that you are from LaConner - Cap Sante Marie will probably sell you what you need. Stellar people.

 

have completed 3/8 ply rabbeted doghouse box

Pics below show the completed 3/8 ply rabbeted 2x2 fir constructed box for my doghouse (engine cover). It has been glued and screwed and has support 2x2's to allow someone to sit on the doghouse (i think) if necessary.

Several questions...and hopefully some of you won't tell me to trash this job (took many more hours to do than i thought it would) and get marine ply or ac ply. The ply was $8.50 at Lowe's but has many knot holes (not ac but must be dd, if there is such a thing!) Anyway...this is what a local has suggested i do...

step 1) generously apply Smith 105 or 'Restore' to the out and inside and ends of the box to thoroughly waterproof the ply and 2x2's. Keep applying until the wood soaks all it can soak.

step 2) make a putty of epoxy and sawdust (1:1 hardner) to fill all the exterior cracks and knotholes.

step 3) sand all exterior surfaces to a smooth finish (not 220 or anything like that)

step 4) apply an epoxy to the finished surface, glass (1.5 oz) and epoxy over the exterior surfaces and ends;

step 5) complete the glass/expoxy finish.

Questions: does this make sense to you experts out there? I cannot seem to find 'Smith 105'...apparently it is quite different than the west 105. Also, if I am going to finish the 'box' to such a smooth condition. Is there a paint or some other surface i could apply to the 'box' that would be adequate?

As you can tell...i am a newbie...and would really appreciate some input so i don't totally screw this up and can have a doghouse (i don't have to live in) and that will last me as long as this glasply.

Thanks

 

You're gonna have a lot more money in the epoxy and fabric than what you have spent thus far. It needs more radius if you are going to wrap the corners. Certainly, places where the plywood's void repairs are probably falling out of that stuff need to be filled. It looks like it has a hatch and cover - how are you going to address glassing that? I would consider just sealing this and plan on building new later. Write back in six years... good luck