TOPIC: Replace wood in fiberglass stringers

Anyone with any experience with this matter - floor on my 1968 starcraft TR-17 was spongy. Pulled it out and of course all wood is rotten and gone or rotten in place - can i cut the tops off the fiberglass forms - add wood then re - fiberglass ? after all the prep required to bond .

That's exactly what I did. Worked well. I used the cut out wood as a form (where I could). I can't remember if I used epoxy or fiberglass to re-seal. I know I used fiberglass tape. I think I had to fill in some voids where the stringer wasn't as wide as the "walls".

Copy that - Only thing i could figure - saw some talk of filling with expanding foam - Don't know if that would last - obviously lots of water over the years - think i might look into poly carb lumber - thanks for the reply - Buster

I've heard the polycarb wood has significantly less stiffness than real wood - something that causes issues when used as stringers. But YMMV, I've never tried it.

I cut everything away but leave about an inch of the fiberglass channels that held the stringers. Then I make new stringers out of either white oak or African mahogany, coated with CPES, and bed them in the channels with 3M 5200, making sure that they are plumb, level and match the original floor height. Then I add foam and cut it level with the other framework which has also been coated with CPES. After that, all is carefully fiber-glassed and I run the fiberglass about 4" up on the bulkheads so that it's impossible for water to enter. I have no idea how long the new stringers will last but it's for sure that this method is better than what the factory used when new. However, I AM sure that it will outlast ME!

Nautilus wrote: Then I add foam and cut it level with the other framework

What are you cutting the foam with?

Get lots of 1 quart plastic containers and then make 1 quart foam batches and spread it out as you pour. After it is finished expanding, pour in more where needed but be sure that the finished foam is a little higher than the framework.

Ah-Ha! So you want to know the secret of cutting foam level with the framework, eh? I use a highly technical tool: A 2' length of an old re-sawing band saw blade with Gorilla duct tape wrapped around one end several times. The saw is pulled to cut the foam, not pushed. Cut straight down about every foot or so and then cut out the 1' pieces one at a time. After all the cutting is done, a palm sander with 40 or 60 grit will easily smooth out any high or bumpy spots.

It is because of this method (and other brilliant adaptations) that I was recently invited to join The Illuminati!

I don't recall sending you an invite.