Fiberglass de-laminating

[lilmikepb]

I am using polyester resin and I have pre-coated some pieces of wood and let sit for a few weeks before getting back into it. Other pieces I brush on the resin, then immediately add mat and wet it out. For some reason, after about 24 hours or so, I went to check on the progress and noticed that most of it set up pretty good and is not tacky but one or two spots did not and I can push the mat back onto the wood. There is clearly a gap between the wood and mat.

It is around 93 or so degrees here while I am working on it. I am using a chip brush and ''dabbing'' it on and it seems as though I am getting all of the air bubbles out. I also see other people laying mat past where they want the edge to be and grinding it off. After 24 hours (maybe more) mine is stile somewhat pliable. I could probably grind it off where I want the edge, but I do think that it would try to delaminate.

What am I doing wrong?! Is it not enough MEKP? Wetting it out to much? Not sealing the wood properly? I can take pictures and post them later on tonight, just wondering if anyone had run into these kinds of problems before.

Thanks!

 

[sphelps]

Pics would be helpful .. Make sure when you mix the resin you do it thoroughly and scrape the sides of your cup while mixing ..Any wet spots on the mat ? If it gets wet it will not take resin very well ..You doing big or small area's ...Make sure you clean the area really good with acetone before you start ..

 

[gm280]

Sam is correct. It sounds lie you may not have mixed the polyester resin and the MEKP well enough. It states to mix for at least two minutes. And I actually do that for every mixture as well. Yes that IS a long time but the reason is so it mixes with all the resin. And like Sam stated, scrape the sides of the container when doing the mixing to make sure the resin on the sides of the container get the MEKP mixed in as well. If after 24 hours the clothe is still pliable, that area didn't get the MEKP mixed properly. So grind it off the best you can, and redo those areas. It will still work after those patches. JMHO!

 

[Woodonglass]

For overhanging hardened mat I trim it off with a B&D jig saw that I bought at a Garage Sale for a Dollar!!! You should precoat the wood and let it soak in until it starts to Tack Up. Then recoat with resin and lay your mat. The wood WILL pull the resin out of the mat if it has not thoroughly been pre saturated . I'd recommend using a 4" shortnap roller for the FLATS and the Chip Brush for dabbing at the edges.