cold weather polyester resin use

[mkspike]

I'm "restoring" an old fiberglass kayak in coastal Connecticut, working in an unheated garage. I'm anticipating a couple of days of at least 40 to 45 degree temperatures during the January thaw. Can polyester resin be used at this low a termperature? Thanks MK

[TeddyDiver]

Nope..

[carboncopy001]

u bet u can u just have to promote your resin with some colbalt. make sure u dont add to much will go off really fast we used a couple of drops to about 4liters or just under a us gallon

[ondarvr]

Polyesters will get hard at lower temperatures, the problem is that normally the cure is poor, heating it later may improve the cure, but it can still be incomplete. Use a heat lamp to keep the area warm , just don't get it too close, it only needs to be above around 60F and if it gets too hot you'll cook the laminate.

[carboncopy001]

I have fiberglassed at that tempurture at current designs many times on the island, to add a propane radiant heater would be nice but yes I have glassed at those temps many times especially when cd first was starting out. Yes your resin will be thicker and your work will be heavier with out heat. So I would add the use of radiant heat you should beable to rent one quite easly. The reason for radiant heat is cause it heats the objects and not the air so less chance of a explosion to happen, and cheaper to operate.

[mkspike]

Thanks for all the input. The info on the cobalt additive made for some interesting google searches and sidetracking. I think I'll use a MAS epoxy rather than the polyester. I'll be bonding a 4oz glass cloth to the inside of the old glass/polyester kayak hull - I think the epoxy will form a better, more flexible bond with the old hull surface and one of the MAS epoxy formulations will cure at 40 degrees. Thanks for the help. MK

[keith66]

I use a 1.5 kw infrared lamp for glassing in cold weather, mine is a West system one built by Red Rad, very good but there are cheaper ones on the market, a friend uses an old sun bed of all things with inra red bulbs!
With infra red it does not matter how cold it is the surface heats up real good just dont overdo it!

[Cobra1]

Get a drum warmer. I had a neighbor use a water bed warmer, worked great and stinking cheapper than most items made for warming drum's. And it does get down into the 30's at night in Az. I used a forced air heater 150,000 BTU to heat my place up. Try harbor freight or northern tools, and search the web for waterbed heaters, they do work great.

A gent known for glassing in snow storms in these parts, Homer, Alaska, was using infrared to get some poly to kick in a rented shed - safest thing goin´, right? Somebody knocked a lamp over. A little acitone, a lot of styrene emission, an explosion and fire. Lost the boat, almost the shed with four other boats in the next bays if it were´t for the quick work of another with a handy front-end loader pulling a fully engulfed FRP weiner roaster outside in 10 degrees. Be careful, Keith.
Epoxy fumes are as much of an irritant and just as deadly but a cool thing is you can work cold, turn the heat up at night and come back in the morning to a completed cure. I use it only when there is a purpose, tho, for a number of reasons including cost.