Fiberglass Supply and other Questions

[rwilliek]

Afternoon All - does anyone have a good source for fiberglass online? I haven't really found any source around the house that would have the fiberglass necessary for replacing the transom in our boat (see my other thread).

Also, what materials will I need? I understand I will need 6-Inch Biax tape, CSM, woven fabric, Resin, and some thickener. But how many layers of each? How Should the 'Sandwich' be layered?

I was thinking this order on the interior of the transom:

Wood
Resin
CSM
Biax Tape with woven in the center to match up to the tape.

Thanks!!

Robbie

 

[ezmobee]

Re: Fiberglass Supply and other Questions

US Composites. http://www.uscomposites.com/

 

[Woodonglass]

Re: Fiberglass Supply and other Questions

Here's how I recommend you do a transom. The overlap of the 1708 is 5" on the first layer and 10" on the second. Thickened resin is Cabosil and Fiberglass fibers mixed to the consistency of mayonaise or creamy peanut butter. Make sure to wrap the edges of the plywood with the CSM and try NOT to get any air bubbles.

(click to enlarge)

 

[rwilliek]

Re: Fiberglass Supply and other Questions

Excellent drawing - makes things much clearer!

What weight on the CSM? I'm surprised there is no other woven in there for strength.

 

[Woodonglass]

Re: Fiberglass Supply and other Questions

1.5 oz csm. The reason there is no Woven Roven is the 1708 is a Biaxial Cloth/Mat combination. It is VERY strong and VERY easy to work with. You CAN use woven roven and a lot of guys still do. I just like the Biax, little more expensive but I like it for it's ease of application. A good source for your materials, if you can't get them locally, is www.uscomposites.com

The 404 or 435 Poly resin are both good resin's

 

[rwilliek]

Re: Fiberglass Supply and other Questions

Excellent information.....this gets me excited because the materials are about $300 total (if I can find marine plywood). The quote I got the other day $1800...thats quite a savings.

Time to get dusty

 

[Woodonglass]

Re: Fiberglass Supply and other Questions

You do NOT have to use Marine Plywood. See if your Local Lumber Yard handles MDO.... NOT MDF... MDO plywood. 3/4 " or 3/4" Underlayment Both Use the same glue as Marine Grade, have very few voids in the plys and are significantly less expensive than Marine Grade. Once you cover it with resin it will last for 30+ years...Way longer than you'll have the boat anyway..

 

[Cadwelder]

Re: Fiberglass Supply and other Questions

Hey Wood, nice drawing, but why do you use CSM / Resin and Butter, between the skin and the plywood?

 

[Woodonglass]

Re: Fiberglass Supply and other Questions

Hey Wood, nice drawing, but why do you use CSM / Resin and Butter, between the skin and the plywood?

Good Question! I coat the transom wood with resin first then apply the csm to the mating surfaces of the two pieces and then clamp em together. When dry, I cut it out to final size then coat and wrap it ALL with CSM again paying close attention to the edges. OVERKILL here I suspect but it's what i do. I then drill several 1/2" holes in the transom in preparation for installation and then mix up thickened resin and spread it on the transom and the outer skin and clamp it home. The Squeeze out fills the 1/2" holes and the holes keep me from getting air pockets during the clamp down. Squeeze out around the edges gets filleted smooth.

Works for me.