What type of wood for stringers and floor

[matt1]

Whats best Oak,pine,maple,whats good for stringers.What works best for floors without using Marine.

[diggler]

I used the outdoor treated lumber (the green stuff) that you can buy at Home Depot. I used a 2"x6"x10' piece. The key to making sure the darn thing will last and not rot is just prior to installation, paint it generously with fiberglass resin and then wrap it in matting. Before the resin sets, plop it down into the boat and then use matting and cloth to bond it to the hull.
The stringer, once wrapped and coated with resin, will absorb the resin and making it pretty much impermeable to water. It's kind of nasty working with, but well worth it as it will be stronger and better than the original stringer that was in the boat.

[Taylorman]

I don't think you need marine grade since it will be glassed in. I remember seeing someone say once that fir is the best thing to use. Make sure you put resin on both sides of the plywood for the floor.

[matt1]

Iwas told never to use treated (greenstuff) with fiberglass.
And yes Kevin I remember someone said to use Douglus Fir for stringers and A/B exterior plywood for the floor just wandering If I remembered right.

[dawgdude]

Matt1, I just finished my stringers about 3 months ago in my JETBOAT, and like you I questioned all the good people here on the board about what to use and got several good answers on several kinds of wood. I questioned a bunch of fiberglass repair guys also. The reply I got from all the professionals in the business was to go get some good lumber, no knots or bends. They said pine would be fine. They said the same as Taylorman. If it's done right, it's going to be completely glassed in anyway so no moisture should make it to the actual wood. They told me that the strength of the stringers comes form the fiberglass anyway. I went to Lowes got my 2x4's and went to town. It turned out great. Of course I haven't put the boat in the water yet so it may sink when that happens. :o . Anyway the point is the woods secondary to the glass. Just my 2cents.

[Taylorman]

Diggler,
I totally agree with what you said and how you did your repairs. One question I have for you is how do you keep moisture from getting in the holes that you drilled in the stringers for your motor mounts?

[matt1]

SILICONE

[diggler]

Originally posted by Taylorman
Diggler,
I totally agree with what you said and how you did your repairs. One question I have for you is how do you keep moisture from getting in the holes that you drilled in the stringers for your motor mounts?
Small paintbrush and a little resin. Then a big dollop of silicone as I slid the bolts through. Kind of like KY Jelly and a new virgin girlfriend. :D

[dawgdude]

Right, resin in the holes and rubber or plastic compression washers thru the holes before passing the bolts thru. I also placed a little silicon in the holes before setting them. Make sure you use clear silicon since the colored stuff white, black, blue etc. has an acid in it that tends to attack anything it touches. Was in the glass business for years and I saw first hand what that stuff can do to a finish or other materials.

[Jake W]

DO NOT USE TREATED WOOD the glass and resin will not adhear to it.
Jake:D

[Bow Tie Omega]

After posting this question over a year ago, I had a response from a professional boat builder/restorer, I forget the name, anyways, he recommended kiln dried phillipean mahogany. It is by its nature one of the most moisture resistant, dense hardwoods in the world, which makes it an outstanding stringer. I had to go to a specialty lumber yard for it. The owner of the yard supported this claim saying that only a synthetic stringer could match it, but not beat it. It was a little pricey though, $120.00 for 2 -2"x8"x12' . These things did not weigh anything either. They are now the spine of the BTO. I was told that I could not break these. Hope that helps.......PS, i only wanted to do this once, not again in 5 years

[Roostertail]

A good quality kiln dried fir is all you need for the stringers. It is a semi-hard wood and strong as hell. I used marine plywood for the floor. It was only about 15.00 per sheet more than a good quality outdoor grade plywood
Hope that helps.

[Mopar426]

I used top grade douglas fir. Was really picky about selecting ones that were staight. I scuff sanded them and rounded the top edges so the glass would roll over. My stringers were 16 feet long, so it was a long process. I coated them first with resin and scuff sanded between coats and used good quality cloth for bonding, about eight strips on both sides. The mat is good for sealing, but isn't as strong for bonding. My floor I used 3/4 inch CDX grade plywood. I sanded both sides to a rough finish and resin coated the bottom and glassed in the top with mat, but bonded the seams with cloth. The time consuming part is scuffing the resin between coats to get a good bond for future coats.