Cold Weather Epoxy

I recently started building a MIll Creek 16. My garage in Chicago is insulated but unheated. I keep a small 600 watt heater on low power under a workbench where I keep my paint and epoxy. This area stays about 60-70 degrees and the garage average temp never falls below 40. regardless of how cold it is outside. I'm working on a 2 foot wide 16 foot long plywood "table" I built for this project. When gluing up my joints, I cover them with an electric blanket set on low (wax paper over the glue) and I cover the joint and the electric blanket with an old quilt. Boat surface stays between 70-80 and it seems to work out fine. Any one have a similar expierence, any reason this could lead to problems?



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RE: Cold Weather Epoxy

If the boat surface is 70 degrees, you should be fine.  Remember it is the temperature of the SURFACE that is important, not the temperature of the ROOM.  My basement averages about 50-55 degrees. I used two 100 watt bulbs in metal reflectors to warm up the work pieces, and found that they warmed up the surfaces to 68 degrees in one hour. Possibly less expensive than heating up the room with that 600w. heater.

RE: Cold Weather Epoxy

Only issue I can see is the use of wax paper.  The heat can melt the wax which does bad things to the epoxy.  Also, the wax has to be removed completely before another layer of epoxy or any finish is applied.  Make sure you clean it very well or find something else to use as a barrier.  Maybe some 4-6 mil plastic.

RE: Cold Weather Epoxy

Thanks for the feedback. The heater under the workbech is independent of the work I am doing on the boat, it is on whether I am building a boat in there or not. Good tip on the wax paper, I'll keep an eye on that and consider using the plastic. Any tips on removing the Joubert Marine Plywood sticker? Mine will not come off except in 100 different pieces.

RE: Cold Weather Epoxy

Good idea with the electric blanket.  I did a cold weather build with a tent and small space heater/heat lamps.  I found that if I had the boat and epoxy warm and did the work I could leave the space get cooler and it would cure overnight.  I e-mailed the MAS representative who said with the slow hardener it was OK down to about 40, just would take longer to cure.  Boat came out fine. 

Yeah, those stickers are a pain.  I got mine to peel off but it left a residue/dark mark that I tried to sand off.  Got most of it off, but still there if you know where to look.  I also had tatoos along one side of the short edges of the plywood pieces that went pretty deep.  I was somewhat afraid I would sand through the veneer before I got them off. 

Good luck and have fun!

RE: Cold Weather Epoxy

I've received Joubert and Shelman from CLC. For one brand, the sticker peels off very nicely, but leaves a nasty residue. For the other brand, the sticker shreds, except where it leaves a nasty residue. In both cases I've had good luck with a ROS and #120 paper to clean off the residue and paper.

Those tattoos, on the other hand. They're every bit as permanent as Kathy says. It'd be really nice if CLC would look carefully at the wood and the expected cutting pattern before they ran it through the CNC and arranged the wood to avoid the stickers and tats on the final pieces.

I guess we could just decide that the tats show that we care enough to buy BS1088.





RE: Cold Weather Epoxy

My garage averages around 55 degrees most of the time.  I have a small electric heater that kicks in if it goes below 50. 

The strange thing is that at this temperature the epoxy still hardens up nicely in less than 24 hours.  I epoxied the stem joints yesterday at around noon, went in to check this morning at 8:30 and the epoxy was quite hard--passed the "thumbnail" test.  I pressed pretty hard with my thumbnail and did dot get a discernable dent.  The temperature was about 58 degrees.

In a way this has me worried that I am not doing things properly.  I am using MAS epoxy with the slow catalyst.  As I said the epoxy is hardened, but I suppose it is not actually cured.  The reason I say that is that because of MAS's literature a full cure at 59 degrees would take 10 days.  This is a little confusing also because their lit states that a cure at 77 degrees would take 5 days, whereas CLC states that it takes 24 hours at 75 degrees.  (This is becoming enough of an issue that I think I'll copy it an add it as a separate post.)

RE: Cold Weather Epoxy

You are doing things right. 

By "full cure" MAS means that the epoxy has reached full strength.  The epoxy will be hard long before it is fully cured.  Here's a page from the MAS epoxy site that has more detailed information on film set vs. full cure times:

You can (and should) re-coat as soon as soon as the epoxy surface is tacky; the epoxy will be quite strong (joints will be stable) as long as it is hard enough passes the thumbnail test, but it will not reach full strength for many days. 

I'll repeat this post in your next post for people who are reading these strings in the future. 

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