How cold is too cold?

[JoeGrz]

Winter has come on abruptly for me and I’m sure others. Since my build has dragged on longer than anticipated, I am curious about when is it too cold to apply finishes? I am applying spar varnish, fiberglass resin and then Monstaliner. Monstaliner says it can be applied in the cold but needs to be moved to a warmer area to finish.

The question I have is at what point do I finish the carpentry and put it away and wait for spring? I know I need warmer weather to apply finishes. What is that minimum temperature?

[saltydawg]

Epoxy is based on the hardener, some will cure in 40 degree temps some need 80 degree. Even one that says it needs 75 degree will cure at 50 degree temps but it can take weeks. I am currently using a hardener that states 75 degree temps and a cure time of 4 hours at that temp, it is curing after about 16 to 18 hours at 55 to 60 degrees but I mixed it at 65 to 75 degrees. Be careful as a hardener that says a pot life of 15 mins at 75 degrees will kick even faster at 80. For epoxy try to keep it about 55 to 60 degrees for the stated cure time and expect it to take 50 to 100% longer.

Varnish is another that will cure at lower temps, it just takes a lot longer as well. They do make additives for some varnishes to speed up the cure.

Monsterliner I have no clue

[tony.latham]

I know I need warmer weather to apply finishes. What is that minimum temperature?

I just don't know.

I glanced at your location and kinda got a chuckle out of this, "how cold is too cold."

Yesterday morning it was 7º up here in the middle of Idaho. But at least it's been brilliant blue days.

I really like the Minwax oil-based poly. They advertise it as fast drying and it is. It's even quicker if you can get some sun on it. On occasion, I've done the first coat with the oil-based and then finished off with one or two coats of their water-born poly over the top of it which is extra-fast drying. That may sound a bit like painting over oil-based paint with latex but it's not. For me, it works. (The oil-based coat is to bring the color of the wood out of course.)

My gut says you'll have to cherry-pick your weather...

Tony

[John61CT]

A plastic greenhouse liner and jerry rigged framehouse,

with a thermostatically controlled forced-air heater blowing

can maintain 60-70° pretty easily

[working on it]

...I really like the Minwax oil-based poly. They advertise it as fast drying and it is. It's even quicker if you can get some sun on it....

* I polyurethaned/painted my 4x8 at both extremes of the weather, at least for N.Texas...not Panhandle-type weather (it actually snows up there!). I used oil-based Min-Wax poly, mixed with thinner for my base coats, quickly followed with paint, at over 100 degrees in blazing sunlight, and also paint+thinner (no poly, except on the floor and along the bottom wall seams, since the exterior and both sides of the doors were already water-proofed with poly) between 80 and 45-40 degrees inside (even mixed with 25% thinner, it started to get thick below 40 degrees).

* I painted the interior in either Jan-Feb ?, using a small space heater to warm the interior up to 80 degrees or so (so the paint would adhere, and cure). I had to paint in stages, pulling the heater out while I was inside, and stopping the painting when the temperature dropped inside below 45-40 degrees. Then, I would re-heat until I could resume. Took me two days, over two colder weekends. I didn't mind the fumes (I used to build Military models in a small, closed room in the 50's-60's..."smells like Victory!"). But, a word of caution; don't wear your only good pair of glasses when painting a ceiling in a 4x8 trailer, only inches above your head. Dries quickly, and irremovable from plastic, coated lenses!

[Squigie]

My rule of thumb:
Unless it's an emergency or special case, finishes, coatings, sealants, and paints don't come out to play once the temperature is below 60 F. --Unless I can use them indoors with household heat, or some space heaters and heat lamps in the garage (and the garage is available - see "automotive stupidity" below).

It just takes too long for most of them to cure/harden/dry.
In some cases, they never cured/hardened if applied in cool weather.
(My 60 F cutoff used to be lower. But after I had a major failure with an epoxy paint applied at 65-60 F, while claiming 55+ was fine, I increased my limit.)

Once our daytime temps are in the 50s, work stops on big projects and I turn to automotive stupidity* and firearms projects* until Spring.
Or, in terms an outdoorsman might understand better: Once hunting season hits and all of the Aspens have dropped their leaves, it's time to change lanes and go to the 'winter projects'. Other trees are unpredictable. But when the Aspens give it up, winter is here.

I am rarely ready for it. There are always things *that* close to being finished, that I would like to continue working on, but I have had to come to admit that it's best if work stops for the winter. But, I am not far from Tony (same weather here this week, as he mentioned). Our winter is quite a bit different than the Texas panhandle. You should be able to keep at it for most of the winter, as long as you avoid cold days.

-----

*This year's priorities:
-4x4 S-10 Blazer semi-restoration and V8 swap, with the added complication of using the factory computer to monitor (but not control) a carbureted, HEI ignition, dinosaur of an engine. I obtained an excellent condition donor vehicle for $400 with a seized engine. A little bit of work (aside from the engine swap) will have it looking brand new by Spring.
-Marlin 336 with every part customized, restored, scratch-built, or machined as a one-off part; as a short, handy, one-of-a-kind little carbine. Two little bits of shaping left, and then it's on to metal and wood finishing. This has been a multi-year project, as others have come and gone from the work bench. But this winter is the one. This rifle will be finished by Spring.

[tony.latham]

It was cold enough here for a fire this morning...





Tony

[JoeGrz]

It sounds like I need to do what I can when the temperature raises. It was a whole 30 degrees today but it is supposed to raise up into the 60s this weekend. If it does, finish the few pieces I have ready. After that, do my carpentry and be ready when the temperature raises up again. Not an efficient plan but probably the one I would be happiest with. Since I need to fabricate a trailer chassis, it may be time to learn to weld

Tony - looking through your window, you have a critter that would like to enjoy that fire

Thanks all for the input

[Tom&Shelly]

It sounds like I need to do what I can when the temperature raises. It was a whole 30 degrees today but it is supposed to raise up into the 60s this weekend. If it does, finish the few pieces I have ready. After that, do my carpentry and be ready when the temperature raises up again. Not an efficient plan but probably the one I would be happiest with. Since I need to fabricate a trailer chassis, it may be time to learn to weld

Tony - looking through your window, you have a critter that would like to enjoy that fire

Thanks all for the input

Sounds like you're getting the weather we had in Albuquerque the past few days. Afraid I can't add much to the discussion. We Monstalined last April, but it was in the garage. Had the doors open for ventilation while applying and then turned on the heater overnight to keep it in the high 60's.

My neighbor has a critter like that one in Tony's yard. Usually shows up right before bow season and just stands there and takes the arrows!

Tom