need fiberglassing help

[shady]

I mixed up some resin and used it and it isn't hardening...... I was making a small batch and used what seemed like too much hardener to me. But I figured id be using it fast so it was fine.......

but its been over an hour and its still a viscous liquid

what do I do if I didn't have enough hardener in it...?

I had a batch harden in the bowl the last time I made it up.... I don't know whats different?

 

[rampage]

It'll just take longer to harden. Is it colder out than the last batch you made? You could add heat to speed up the process, like a space heater or heat gun. Just make sure it's not in a confined area that the fumes will build up in.

 

[shady]

its in my garage..... but the fumes are getting into the house so doors are open now.... its cold in there.... but it was warm in there for about a 1/2 hr

 

[rampage]

You're taking heat away from an exothermic reaction. If you make up a batch and add lots of hardener to it you'll notice the container gets too hot to pick up. Yeah, I experimented once and my plastic container melted from the heat.
I had something I made that didn't set right away. Came back to it the next day and it was hard.
What did you make, or is it top secret?

 

[ryoken]

I pretty much do glass work daily..

polyester resin and MEKP hardener reactions are based on percentages.. %'s can vary from .5 to 5%. depending on temps and other factors, type of repair, thickened, type of glass, etc..

as mentioned, just throw a bit of heat to it for 10, 15 minutes, heat lamp or gun, stop and let cool, it'll be dry within the hr..

a word to wise for people playing with poly... the strongest results are with lower percentages of hardener... yes, higher %'s will kick it quicker/hotter, and harder initially, but also be MUCH more brittle... sometimes that's not critical, sometimes it's MUCH more important..

I could definitely write a book on fiberglassing...

 

[shady]

thanks guys.... heat lamp on it now. its for my speaker box and on my kick pods im making. hopefully ill be able to get a bunch done on my burbs stereo while my kids blazer frame is getting sandblasted and primed. gonna be busy when it gets back

 

[rampage]

a word to wise for people playing with poly... the strongest results are with lower percentages of hardener... yes, higher %'s will kick it quicker/hotter, and harder initially, but also be MUCH more brittle... sometimes that's not critical, sometimes it's MUCH more important..

That's good to know - stored for future glass work.
I was just experimenting with that batch when I added an excessive amount of hardener, didn't use it for anything.
I'm sure that's mentioned in this book I have. It's been many years since I read it.
http://books.google.com/books/about/Fiberglass_Composite_Materials.html?id=ileMYXGZ3OQC

 

[ryoken]

another tidbit most don't know is how quickly and violently poly resin kicks is not only based on MEKP % and temp, but how vigorously it is mixed..

if you take 2 different gals of resin, side by side, add the same hardener to each, mix each for one minute, one with a paint stick, the other with a paint mixer in a cordless drill, the whipped one will kick MUCH quicker and hotter..

 

[shady]

heat lamp did it. I also turned the heater on and just dealt with the smell in the house. it cleared up rather quick though..

thanks again guys