styrene activation

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styrene activation

Postby Guest » Tue Apr 10, 2001 12:57 pm

I am about to repair a fiberglass crack and I plan to follow Don Casey's method. However his method calls for wiping the old fiberglass area with styrene to reactivate the old fiberglass resins for better chemical bonding with the new resins. Would anyone with fiberglass experience tell me if you use this chemical during your repair? Can the repair be done without it? I only ask these questions because styrene doesn't seem to be readily available.

Rick Dennis (dennisrl-at-us.ibm.com)
Guest
 

Postby Guest » Wed Apr 11, 2001 6:58 am

Rick,
I am in the process of refurbishing my 1974 DS II which includes repairing everything from dings, scrapes, and gelcoat cracks to a 5 inch long gash in the hull. I have used West System products and followed the directions in thier book with great results so far. Basically you sand the repair area w/ 80 grit paper, paint with epoxy and then add your cloth or faring compound mix. After this cures you sand it down w/ 80 grit then 220 grit. I am painting the boat w/ Interlux Topside polyurethane, again with great results, after mitculously following their directions. I was a little intimidated by all of this at first, especially after reading the directions, but once you get started, its really pretty easy.

Jim (jimb-at-dsouth.com)
Guest
 

Postby Guest » Wed Apr 11, 2001 7:57 am

I had to repair a really big spider crack in my hull because a rough boat ramp rocked my boat down hard onto a roller on my trailer. I cut out a hole larger than the cracked area and made sure that the corners of the hole were radiused (no sharp corners) then beveled the edges (about 8:1). Since the hole was on the hull side of the flotation seats and not accessible from the inside, I made a mat of about 5 layers of glass onto a piece of cardboard and put a loop of wire through so that the ends stuck outside when the mat was inserted against the inside of the hole. The mat was about 1 1/2" larger than the hole on all edges. I tied the wires to a "bridge" of wooden slats that spanned the hole to keep the mat against the inside until the epoxy set up. Once set up I ground off the wires flush then started to build up the thickness of the original hull with alternating layers of glass mat and cloth. It is important to make the first layer go all the way to the outside of the beveled edge area then progressively use smaller sized layers as you build up the hull thickness so that when you do your sanding to fair the repair to the hull shape you will not cut into the continuous strands of glass laying against the bevel which would weaken the bond. Build up slightly above flush, cover the repair with plastic food wrap to make the surface set up hard, sand back to flush starting with coarse paper and ending with #120 or finer paper then paint. I used acetone to prepare the existing glass surface for bonding. I think the main thing is to get any wax and/or oxidation off the surface that might prevent bonding.

Calvin Trotter (calvin.g.trotter-at-saint-gobain.com)
Guest
 


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