i really want to get my boats deck in and want to know how cold is it to not be able to fiberglass. its bin below freezing most the days and nights here is should start warming a bit up but any help would be great. and also if i get one day and night that it's about freezing what temp is good to fiber glass in.
It pretty much depends on the resin you're using. Some slow epoxies work best above 80, with some fast epoxies you can go down into the 60's. I've used polyester resin down into the mid 50's by increasing the amount of catalyst, but that was for non-structural stuff and doing that isn't generally recommended because the resin doesn't cure properly. Another thing you can do is use shop lamps (with incandescant bulbs) as heat sources to keep your work warm as it cures.
so if i get a 40 degree day and use heat lamps i should be good?
Well, that depends on a lot of variables. 40 degrees may be pushing it. And what type of resin are you using?
If you use shop lamps to provide heat you still have to start out with resin at room temperature, so store it in the house for several days prior. Also, before you start spend some time checking out your lamp placement to make sure that ALL areas of the work will be warm enough, but not too warm.
Don't just jump into this without taking some time to make sure you've got all bases covered. If any portion of your layup isn't up to temperature it's not going to cure properly, be very careful about that. Also, it is possible to get the layup too hot, that can be just as bad.
Finally, guess how I know about what can go wrong doing this ..... Yes, I've screwed up a few parts along the way.
40 is REALLY pushing it- I wouldn't do it. Remember, it will take a LOT longer to cure at those temps, and you'll need to keep it warm the whole time- NOT just when you're applying it. I put my floor in when it was in the low 50's- But I had it inside a garage, and heated the work area to about 60 for the entire time it was curing, using space heaters. It still took FOREVER to cure.
Judging from your last photos, there's PLENTY that you can do before glassing the floor in. Take your time and do it right, so you only have to do it once.
im with the other guys if your not going to have it in an enclosed garage with a proper heater that will heat the entire work to about 70 degrees over a period of about 3 days (1 day just sitting to bring work to temp fully, 1 day to work and apply, and 1 more day to fully cure) i wouldn't do it. i did my glassing in winter but like i said i was in the garage, sealed up, with a blast furnace going the entire weekend
i have done several threads on glassing in colder temps.
it can be done.....BUT....the conditions must be right....the glass, resin, and substraight has to think its above 70.
on a deck....without a tent...heat...and a few days to warm everything up....it is a waist of time.
The Hull Extension Thread
great info on all aspects on boat building with detailed information.