Finishing in cold temperature

[Pete Kurki]

What kind of hand-applied finish, if any, can be applied in a cold temperature? During this coldest winter time I can still keep my shop temperature at 55 F but trying to get it to over 60 F for finishing is really hard with my current heating methods. First of all, I am a complete novice in finishing, and the only thing I tried so far was a brush-on Minwax product that has stain and poly in one can, and it failed pretty badly in 55 F as the finish would not level as it was supposed to. How warm temperature do I need for wipe-on poly to work for example? The pieces I am trying to finish this winter are red oak coffee table + 4 end tables + sofa table set, and it may be another 3-4 months here until the temperature is warm enough so that I can get the shop to 65-70 F.

Pete

[Steve Schoene]

If you can't get the shop consistently over 60° for several days, and preferably over 65° your only finishing choices are shellac or lacquer, both evaporative finishes. VArnishes, oil based or waterborne, must undergo chemical reactions to cure, and those reactions are dramatically slowed as the temperature drops. You need to maintain the 60°+ temperatures long enough for the wood to completely warm to that temperature, and for at least 48 hours, preferably more, after the last coat has cured. I

By the way, you have been saved by the temperature from using the Minwax Polyshades, probably the worst finish on the market. Almost no one can apply that product evenly enough to be acceptable.

[Phil Phelps]

..a torpedo heater.

[Al Wasser]

Can you curtain off a small area using plastic sheets? Install a heat lamp in the overhead fixture. Bring the finish and the project indoors and get them warm and then take them to the curtained off area to apply the finish and allow to dry. Wipe on finishes might work better under your conditions since you apply a very thin layer each time -- ie danish oil or other wipe on finish.

[Steve Schoene]

Torpedo heaters can dump a lot of humidity as they heat--not a good thing for shops or for finishing.

[Pete Kurki]

Can you curtain off a small area using plastic sheets? Install a heat lamp in the overhead fixture. Bring the finish and the project indoors and get them warm and then take them to the curtained off area to apply the finish and allow to dry.

Not a bad idea. Actually I have plans to expand my shop next summer to have a permanent isolated room for finishing, which will be smaller and well insulated to hold 70 degrees easily. But your suggestion may be worth looking into to get through this winter.

Wipe on finishes might work better under your conditions since you apply a very thin layer each time -- ie danish oil or other wipe on finish.

I had thought along these lines too, so this is what I am going to try now when we actually have a couple of days in 20's and I should be able to get the shop to at least 60 F. Just unfortunate that I think wipe on poly will still be wasted effort in 60 F.

Pete

[Michael Pyron]

when I use my garage as a spray booth I find that I need lots of directed light placed around the room to cover all aspects of the piece so that I can truly see what I am doing....I've had up to 6,000 Watts of lights (that = 12 500 watt halogens) going at one time....trust me, that creates a lot of heat and even with my garage door lifted up just enough for a box fan (with the areas on each side of the fan blocked with plywood rips) I've been able to get around 70° when it was below freezing outside. of course when I spray in the summer I have to use less lights and spray by 'feel' as it were...it can also help to heat up the product you are spraying (if you are spraying)...I've done this by doing my mixing, putting it in the siphon cup and attaching to the gun and placing the cup in a pot of hot water with the gun handle on the outside of the pot...it works beautifully!

and for those of you safety freak pundits that are bound to respond about my 'system' be aware I use sealed lights and keep them out of my booth (in general, though I have brought a couple in for certain situations...I'm still alive). my booth is 4 mil plastic sheeting stapled to the ceiling of the garage and stapled to a 2x4 frame on the ground. the box fan is in its own frame which allows the plastic to be attached around it, and I make a tunnel out of plastic with a stick on the bottom to tie the ends together that gets the stuff to the outside. the booth has to be back from the garage door as when I open it up the top of it of course comes into the garage. I use those cute little zippers that have tape on each side to create a door which I can zipper shut behind me and run hoses through a created opening in the plastic. my compressor is of course NOT in the booth and is on the opposite side of the booth as the exhaust fan is. I've gone so far as to spray both lacquer and thinner directly into the fan (with an extinguisher in hand) to test for safety...I'm thinking most explosions/fires are created by people who don't keep their spray environment clean between coats, I do as I hate crap getting into my finishes....

[Mike Monroe]

My basement shop averages 60 degrees in the winter. I'm currently finishing a blanket chest. The water-based dye and shellac I'm using have dried just fine at that temperature. I just wiped on and off a coat of oil based English Walnut (black) stain this morning to accent the pores of the mahogany. Planning on brushing on a coat of blonde shellac tonight then top with water-based varnish.

[Steve Schoene]

My basement shop averages 60 degrees in the winter. I just wiped on and off a coat of oil based English Walnut (black) stain this morning to accent the pores of the mahogany. Planning on brushing on a coat of blonde shellac tonight then top with water-based varnish.

The dye and shellac are fine in the cool shop, just drying a little slower. But, the oil based stain would be expected to take considerably longer at 60° than at 70°--I doubt it would be ready for overcoating this evening--very few would be at that temperature. I'd give it at least until tomorrow evening.

At 60°, the waterborne finish will be close to absolute minimum temperature to even lay down and form a film. If you want to use this product it would be really wise to devise a way to warm the wood, the finish, and the air for long enough for the finish to cure.

[Danny Thompson]

Try Minwax Satin Wipe-on Poly. I just applied 4 coats over 2 days to the base and underside of a dining table in the garage. Outside temp was in the 30's, 40's, & 50's. Just go with thin layers and add a couple of hours to the drying time.

[Prashun Patel]

Shellac dries pretty quickly. If yr like me, oil-based finishes are frustrating in the winter. They can take DAYS to dry in a basement < 70deg. If yr like me and don't have the patience, then you'll try to sand and put on additional coats before the 1st is totally dry. This just causes all kinds of problems.

[Mark Patoka]

I almost always use a brushing lacquer and never have a problem during cold weather. Lately my garage has been between 40-50 degrees. I do try to bring finishes and glue into the house first to "warm up" before using them but then we leave our thermostat at 64 so it's still not overly warm but I haven't had problems yet.

If you do a search here for the MinWax Polyshades that you used, you'll find that it isn't even worth the Haz Waste disposal fee to get rid of it.

[Richard M. Wolfe]

When you move a piece into a warmer area to finish it let it acclimate to ambient temperature before putting a finish on it. A friend brought some smaller pieces (lucky for him) into a warm room from outside and immediately hit them with lacquer. He then had two things - a real foggy finish (from water vapor condensing on the cold wood).....and a temper tantrum.

Everyone should use Polyshades at least once. Makes you appreciate anything else.

[Mike Monroe]

Warmed up my unfinished finish room in the basement last evening to around 70 degrees with a propane heater. I took the can of Varathane Diamond water-based poly upstairs and set it near the wood burner to warm up. The label on the can of Varathane said apply between 55 and 90 degrees, so 70 should work. After waiting an hour for the blanket chest to warm up I applied a coat of finish. I'd never used water-based poly before and was impressed with how the product went on, flowed out, and dried with a cheap foam brush. The milk like color when applied really helps to see what has been covered and what hasn't. I applied two light coats last night about 4 hours apart. This morning I lightly sanded the piece and applied another light coat. I'll be interested to see how it looks after another one or two light coats and some wax.

[Lee Schierer]

I've used Deft and Cabot brushable lacquers in an unheated garage for all my furniture projects for over 30 years. I have applied finish just this past week at 9 degrees F. with no problems. It will take much longer to dry, so only coat horizontal surfaces to avoid runs. Leave the project out side for several days after the last coat so it dries completely. I can usually apply 1 coat per side per 24 hours when temps are below 32. I keep the project outside between coats and keep the finish indoors unless I'm putting on another coat.

I've also used the Varathane Diamond floor finish and it is a great finish, but is limited to 55 degrees for the low end temp. I believe you shouldn't let it freeze either in the can.