butt joint question

gken · Post by **gken** » Sat Apr 21, 2007 2:58 pm

when I spread the epoxy over the fiberglass to cover the butt joint the frayed edges started to pull out. Is this a problem? I tried to keep it neat, but when i pulled the squeegee over the edges it pulled the strands out. It isnt bad, but you can see them. I can take a picture if anyone needs one to see whats happening. Is there something I can do to prevent this? Does it just happen all the time and is it nothing to worry about? ok....thanks for your help. --Garrett

Post by **jem** » Sat Apr 21, 2007 3:29 pm

Easiest way to resolve this is apply the fiberglass and let it start curing. Wait until the epoxy is still just a little "moist" but starting to get tacky.

Drag a sharp razor blade or other cutting tool across the edge of the fiberglass to trim it to a clean edge. Pull off the excess cloth. Don't press too hard because you'll cut into the wood.

You could also just lift up those stringy pieces away from the wood. Don't tug too hard because you'll pull the cloth out of position or introduce an air-bubble. With the frayed threaded lifted up, they'll easily come off when the epoxy fully cures.

gken · Post by **gken** » Sun Apr 22, 2007 12:25 pm

One more question. I put a light halogen light over the butt joint because the heat should help the epoxy set up faster right? The epoxy is forming bubbles on the surface of the glass cloth. Is that normal or should I not put the light over it? thanks, Garrett

Post by **jem** » Sun Apr 22, 2007 1:41 pm

bubbles are coming from the wood out gassing. The light is probably speeding up that process. I'd waiting until the epoxy sets up past the moist stage. Then you can apply the light to speed the rest of the cure.

gken · Post by **gken** » Sun Apr 22, 2007 9:12 pm

Thanks Matt, I will try waiting. I didnt use the light on the first side, and I didnt have a problem with bubbles. I will let the epoxy set up more in the future before I set up the light. --Garrett

Mullet_Key · Post by **Mullet_Key** » Tue Apr 24, 2007 8:36 am

Also, try two things: 1.) lay a strip of blue 3M masking tape from top to bottom of the panel 3-4 inches from the joint on each side. Lay your fiberglass patch over that section, apply epoxy, but not past the outside edge of the tape. When the epoxy is just beyond tacky, take a very sharp razor blade or carton cutter and trim the glass on the inside of the tape and pull the tape and excess glass away. When no longer tacky, but not fully cured, use a scraper to smooth out the edge, making it more flush.

2.) Cut the glass patch on a 45 degree angle, scrape the edges when nearly cured. Both methods take about the same abount of effort.