Temp vs. Resin

'84Offshore

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I bought Polyester Boaters Resin from West Marine.
Says not to use less than 60*...........it's only supposed to be in the low 40's today?

Whats the risk if I do it today?
 

Doc Stressor

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It just takes forever to set up when it's cold. You won't hurt anything, but it takes too long between coats.

I sealed up the edges of a hole that I cut in the deck of my skiff for a hatch installation last winter. It was still tacky almost a week later. It was cool in NW Florida but not as cold as LI.
 

gw204

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With polyester and vinylester, you can usually play w/ the catalyst percentage to work with different temperature ranges. That being said, if this is the case, it usually says so on the mixing instructions.

What is the catalyst ratio that is mentioned? 1%?
 

JeffN

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I think 40 is too cold, a waste of time and material. That is one of the things I liked about poly when working on surfboards because I could push it some but only so far. Who do you know with a warm garage? If you could get the room temp up into the higher 50s you could warm the panel with quatrz work lights before layup, move them back while you work and then move them a bit closer to keep the panel warm while it kicks. Watch it as they really get hot. Best bet is find a work area you can get into the 60s, you only want to do this once.
 

ROBERTH

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I use the Halogen shop lights and put just over the surface to be cured. You would be surprised how much heat they put out. Just make sure you don't put them too close and keep an eye out not to overheat the surface. Leave them on long enough to kick off the resin to allow the wax to surface and then cure. If you get it warm, it doesn't take long, like no more than an hour or two in cool weather.
I have heard that using polyester resin when too cold, it might not cure properly and could have some bonding issues or soft resin.

I will be trying to spray some gelcoat this weekend in low 60's, but will move project into garage and turn on heat and heat lamps to ensure gelcoat cures properly. I can get my garage up to 80 degrees so will be no problem, but if outside, definitely use heat lamps. I did use roller/brush tipping early spring on transom and used heat lamps to kick off and it worked out fine.