# Preparing a shop for sub-zero temperatures



## ThinWoodsman (Sep 22, 2018)

I know the how-do-I-heat-my-shop-in-winter topic has been done to death, so I'll try to keep this pretty limited in scope.

Recently, I reached the limitations of the shop in my basement with its benchtop equipment. There is a barn on my property with a concrete pad the size of a single car bay. To make a long story short, I built a shop on that pad, and acquired some full-sized machines (14" lathe, knee mill). The walls and ceiling of the shop are insulated (~R21 on the walls, ~R30 on the ceiliing), but the concrete pad is not. The shop is 12x28 ft, so 336 sq ft.

Winters here (NH) get cold, 2018 being a great example - about three months solid where it didn't get above freezing, with lows somewhere around -10, -15 degrees for a week or two at a time.

Ideally, I would heat the shop 24/7 to 35-40 deg (F), but that seems impractical for reasons others have mentioned. So I'm looking at some sort of as-needed heat: a kerosene/propane heater with the door (into the rest of the unheated, uninsulated barn) open, or an electric heater.

What I would like to know is: what are the drawbacks to leaving the shop unheated in such conditions? Specifically, do oils and solvents and the like need to be removed from the shop during winter? Do sensitive measuring instruments (dial indicators, micrometers, gage blocks/pins, etc) suffer from being stored so far from their operating range? Will repeatedly heating the room from well-below-freezing temperatures cause long-term problems in any of these?


----------



## JimDawson (Sep 23, 2018)

With the insulation that you have, I would say a small electric heater might be practical to leave on during the cold weather just to keep the shop above freezing.  Maybe 1.5 KW or so.  Then when you want to work in there about a 50K BTU propane heater would warm it up quick, maybe one of the radiant types that are designed to operate in a closed space.

We don't have weeks of really cold weather so I don't heat my shop (1200 sqft), and I'm not insulated near as well as your shop is, but when it's cold I fire up my 150K BTU propane torpedo heater and point it directly at the machines from about 10 feet away to get them warmed up before I run them.  Maybe give it a couple of hours to warm the machines up until they are warm to the touch.  If I'm going to be in the shop for extended periods, then I fire up the wood stove.  I leave the computers & DROs on all the time.

Storing measuring tools at low temperatures won't hurt them, but don't try to use them when they are really cold.  You could keep the tools in a tool box and bring them into the house.  I keep some of my precision tools in the house during cold weather.  At the temperatures you are talking about humidity is not going to be a problem.

Petroleum based oils & solvents won't be affected by cold weather, any water based solvents and cutting fluids could freeze or separate if cold enough.

The biggest problem we have here is an extended period of cold & dry, then a quick warm up with high humidity.  Everything sweats, so when I know that it is going to warm up like that, I fire up the wood stove to dry out the shop.


----------



## ThinWoodsman (Sep 23, 2018)

Yeah, I know all about humidity - left for a week in August and came back to not only rust, but mildew growing on the just-installed walls of the shop. Bought a dehumidifier that's plugged into a timer to run it for an hour in the afternoon and an hour in the early morning. Seems to have solved the humidity problems.

Re: petroleum-based products and measuring tools: that is what I suspected, but I'm hesitant to ruin a gallon jug of way or circulating oil. For the measuring tools I was worried about metal creep due to the repeated warming/cooling (if shop is not heated 24/7), but looking into it more it appears that would be due to the small size of the devices and the relatively low temperature they'd be raised to (~60F).

For the first winter, I think I'll leave some consumable (read: cheap) dial indicators in the shop, along with filled oil cans. The expensive instruments and the gallon jugs of oil can be stored in the house until I can verify, come spring, that nothing got ruined.

Good idea on doubling up the electric and the propane/kero heaters. I may give that a go.


----------



## Bob Korves (Sep 23, 2018)

Flame heaters that run on hydrocarbon fuels (gasoline, oil, kerosene, propane, natural gas, etc.) react with oxygen in the air when they burn.  The result is that large quantities of H2O (WATER) is produced along with with the heat.  With an heater that is not externally vented, the shop will be dripping with moisture, especially when it cools down again.  Opening a door or similar helps some, but by no means completely, and also lets your precious heat go out the door or window.  If there is a way of installing a chimney, you will be much better off when burning fuels in your shop.  Electricity works great in a closed room, no fumes, no cold air coming in to burn the fuel, and no energy going up the flue.  Depending on costs in your area, the price of electricity can be quite high or pretty reasonable in comparison to burning fuels.  Efficiency numbers and cost of installation and fuel must be factored in to figure out what is best for your situation.


----------



## T Bredehoft (Sep 23, 2018)

From personal experience, one may work comfortably in an indoor shop with the temperature near or above 45ºf. Sure, you gotta dress for it, but you don't start chattering. If you could maintain that temperature with an electric heater, You could go to work and turn up the heat for a warmer place after a while. Or, keep it at that temp.


----------



## Karl_T (Sep 23, 2018)

Once that concrete floor freezes solid, its dam near impossible to get the shop warm. Been there done that in Minnesota. I suggest radiant heaters, either electric or propane, use them to keep you warm. Works pretty well if you are running the lathe or mill. Not so much if you need to move all around the shop. before I got my heated shop, I also just gave up for about six weeks in mid winter.


----------



## gi_984 (Sep 30, 2018)

Been there done that.  Second the problem with the block of ice called the concrete floor.  If at all possible keep it at 40 to 45 degrees ambient inside the shop all the time.  Tried to use the kerosene torpedo heaters and the high end Kero Sun kerosene radiant heaters.  Fumes to choke you out and stink.  Plus it took forever to get the temps up.  The circulating oil in the machines was the consistency of molasses.  The machines just stayed cold even when the air temperature in the shop warmed up enough  to work comfortably.  Rapidly became not worth the effort once it truly got cold.  My only regret with going to a fully insulated shop and heat was waiting so long to do it.


----------



## Dabbler (Oct 1, 2018)

It is good to cover the entire floor in an insulating material.  The 2' X 2'  basement tiles that are OSB bonded to styro work very well.  place them everywhere, and your heating bill will be lowered by more than the cost of the tiles.

I used to keep my shop heated to 5C (41F)  but now I do it to 8C (47ishF).  I can work on the machines after only a little heating of the air in the shop, and the condensation has gone waay down...


----------



## hman (Oct 1, 2018)

... and even when cold, such a floor will draw a HECK of a lot less heat from your feet!

[edit] - Don't have the problem myself here in Arizona, and we live in a well drained area, so the anticipated heavy rainfall from the remnants of Rosa will not be a problem.  But I used to have a garage/shop in Oregon.  Covered much of the floor with interlocking foam mats.  I can certainly appreciate the value of your solution!


----------



## uncle harry (Oct 2, 2018)

T Bredehoft said:


> From personal experience, one may work comfortably in an indoor shop with the temperature near or above 45ºf. Sure, you gotta dress for it, but you don't start chattering. If you could maintain that temperature with an electric heater, You could go to work and turn up the heat for a warmer place after a while. Or, keep it at that temp.



Latex gloves (thin ones) keep fingers warm by avoiding perspiration evaporation cooling.  My assistant friend & I use small ceramic electric heaters to warm our feet when working in one spot while waiting for the furnace or wood stove to catch up depending on which shop we are in.


----------



## Janderso (Oct 2, 2018)

Dang, I have never had to deal with temps that cold.
It seems like the infrared style gas people heaters would be the most efficient and affective.
That’s what we use at the dealership. Each stall has a people heater above their work area.
Cold to us is in the 30’s and 40’s though.


----------



## NortonDommi (Oct 2, 2018)

Just spring here and I'm going to sound like a wimp since the coldest it gets is about 1 degree C [34F]maybe overnight but high humidity and those Southerlies are straight off the Alps. By next winter I intend to have a couple of the newer infrared heaters with variable output.  The one I bought was an outdoor model and needed to much clearance so I gave it to a friend with 5500 square feet of shop. It is mounted high up and works on his workbench area. Very pleasant underneath and all the tools are warm like they were in the Sun so no cold fingers.  I like these as they warm objects and then the objects radiate heat which stops condensation. There are a lot of waste oil burner designs around as well which blast heat out.  I can't even imagine the temperatures that seem normal to some of you.


----------



## magicniner (Oct 2, 2018)

Put insulating floor matting down to cover all areas not occupied by heavy machinery and run a dehumidifier, use a timer for On/Off periods as necessary. 
That will keep the temperature up and remove the water you add to the shop.


----------



## CluelessNewB (Oct 2, 2018)

I have an externally vented Modine "Hot Dawg" for my shop. It costs a bit more than a portable but doesn't add additional humidity and there is no need to keep a door or window open.  My last shop had a wood stove which worked ok also.  The propane is a bit more convenient and allows me to keep it heated for a few days unattended if required for things like paint drying.  I do miss the wood stove at times.      

https://www.modinehvac.com/web/prod...-heaters-hotdawg/hot-dawg-power-vented-hd.htm


----------



## magicniner (Oct 2, 2018)

There's no point having externally exhausted gas heaters in a shop where you allow humans to breathe out ;-)


----------



## Dabbler (Oct 2, 2018)

I have a gas heater in my shop that is ceiling mounted, much like a Hot Dawg;  It keeps things quite dry and cool, but not too cold.  I have a 50,000 BTU unit for a 650 Sq Ft garage.  I insulated it to R12 in the bad old days;  now I am reconsidering putting much more in.

My shop floor is only partially insulated as well, something that will get fixed this winter!


----------



## NortonDommi (Oct 2, 2018)

magicniner said:


> Put insulating floor matting down to cover all areas not occupied by heavy machinery



  That friend I gave the heater to I also delivered several truck loads of off-cuts from a wood supply company.  These were 4" x 2" of assorted small lengths when timber was cut to length and any blemishes removed.  I thought I was supplying firewood but he used them to lay down a Parquet floor over the concrete slab, all except for an area where stuff like bulldozers or other vehicles go to be worked on.  Glue was the only cost and it is great insulation, very hard wearing too.


----------



## hman (Oct 2, 2018)

NortonDommi said:


> Just spring here and I'm going to sound like a wimp since the coldest it gets is about 1 degree C [34F]maybe overnight but high humidity and those Southerlies are straight off the Alps.


OK.  Now please educate this geographical ignoramus.  Which Alps are you talking about?  Surely not the Swiss Alps (which are on the far side of the Equator)????


----------



## NortonDommi (Oct 3, 2018)

Hi hman,
                 Southern Alps which run up South Island.  Some days in Winter the wind comes up from Antarctica and travels up along the Alps, across the straight then hits a couple more mountains and goes through my bones like an ultrasonic razor-blade.  One of those lazy winds that goes through you not around you.  Here's a You Tube of a helicopter flight from a station to Milford.  Good hunting grounds.


----------



## ThinWoodsman (Oct 6, 2018)

Yeah, I've had plenty of suggestions from neighbors on heating the space - most of them just went all-in and installed a vented heating system for their detached workshops.

For now, I'm okay with abandoning the shop during sub-zero temps, as I still have a basement shop to work in, and that stays above freezing.

I'm more worried about damage to machines/instruments/materials caused by exposure to these temps, but as Jim Dawson mentioned this is likely to be negligible. Cold storage it is, then.

EDIT: I did purchase a small electric oil-filled (radiant) heater and will be using that to keep the space above freezing until it can no longer keep up. I'll try to remember to update this with how it worked out in around Feb.

Thanks, all.


----------



## Boswell (Oct 6, 2018)

ThinWoodsman said:


> I did purchase a small electric oil-filled (radiant) heater and will be using that to keep the space above freezing until it can no longer keep up. I'll try to remember to update this with how it worked out in around Feb.



I also use a oil-filled radiant heater. I have an insulated shop with exposed concrete floors. I put the heater on the floor behind my lathe and it does not take up any otherwise usable floor space. Keeps the shop very comfortable in the winter. 
But of course I am in Central Texas and while we do get a some days each year below freezing it is rarely very many so this work to keep the shop comfortable.  The exposed concrete is so it will help keep the shop cooler in the summer which is much more of a concern.


----------



## ThinWoodsman (Oct 7, 2018)

"For optimal storage, maintain product at a
temperature between 8°C (46°F) to 21°C (70°F). Storage
below 8°C (46°F) or greater than 28°C (82°F) can adversely
affect product properties. Cyanoacrylate products must be
stored under refrigerated conditions at 2°C (36°F) to 8°C
(46°F). Storage below 2°C (36°F) or greater than 8°C (46°F)
can adversely affect product properties."

Looks like the Loctite will get kept in the house.


----------



## Karl_T (Oct 7, 2018)

ThinWoodsman said:


> ...
> 
> I'm more worried about damage to machines/instruments/materials caused by exposure to these temps, but as Jim Dawson mentioned this is likely to be negligible. Cold storage it is, then...



I suggest you get a Sureshot sprayer. Fill it with motor oil thinned with diesel. Spray all the metal surfaces. Stops rust and is quick to apply.


----------



## eugene13 (Oct 7, 2018)

Mobilmet soluable oil should not be allowed to freeze.


----------



## ThinWoodsman (Oct 9, 2018)

Karl_T said:


> I suggest you get a Sureshot sprayer. Fill it with motor oil thinned with diesel. Spray all the metal surfaces. Stops rust and is quick to apply.



Yup! Been doing that since the problems with humidity this summer. Beats the pants off using a brush - those sureshots are great. Gave it a go applying way oil to the lathe after its first real cleaning - results were a bit mixed (ways oiled very quickly, but with too much oil).


----------



## ThinWoodsman (Oct 9, 2018)

eugene13 said:


> Mobilmet soluable oil should not be allowed to freeze.



Thanks for mentioning that - I don't use S-122, but it reminded me to check up on the cutting fluids I use. The Oatey dark cutting oil is fine, of course, but the SDS for Tap Magic (Aqueous) lists its freezing point as 32F and includes "do not freeze" on the storage requirements.

Between that and the Loc-tite, it looks like an evening of downloading SDS PDFs is in order. Only way to be sure.


----------



## Downunder Bob (Oct 9, 2018)

I don't know how you people live in those below zero temps. A pity you didn't put some hydronic water pipes in the concrete slab when it was poured. I imagine your barn has quite a high roof, so you could raise the floor level and put some pipes in as you do it, then set a thermostat at say 5c for standby and just add some extra heat when you're in the shop, A flued propane  or wood burner, or electric whatever suits.

Even in Australia where I live the midwinter min is rarely ever below about 5c my garage shop is heated to 15c by a hydronics setup running of a wood burner, that heats the whole house to around 22c. So condensation is never a problem, and I can work in the shop with only a light jacket over house clothes.


----------



## fradish (Oct 9, 2018)

I thought this post was an exceptionally clever way of dealing with condensation on machines
stored in unheated spaces, or at least in spaces where you don't want to heat them all of the time.

https://www.hobby-machinist.com/threads/my-condensation-management-setup-worked.67601/


----------



## eugene13 (Oct 9, 2018)

I did, and I heat with Coal, both the house and shop.  We have a humidifier in the house but my shop is dry, no problem with condensation or cold.


Downunder Bob said:


> I don't know how you people live in those below zero temps. A pity you didn't put some hydronic water pipes in the concrete slab when it was poured.


----------



## Downunder Bob (Oct 10, 2018)

We haven't been allowed to use coal here for as long as I can remember, but we do use wood, mostly red gum, also known as Red River gum, Eucalyptus camaldulensis  about the best firewood you can get. It's an Australian native, but now grown all over the world, mostly for firewood. I've even read that in Brazil they use it for smelting steel.


----------



## JPigg55 (Oct 10, 2018)

I live in west, central Illinois so winters aren't quite as cold as yours, but can get very cold for extended periods.
My shop is built in a 20' shipping container, big metal box although floor is 3/4" plywood. I framed up the interior with 2x4's sheeted with 3/4" tongue and groove OSB and fiberglass roll insulation (floor not insulated). Not near the R value you have and square footage isn't as much, but I can keep my shop comfortable 24'7 with a single milkhouse style electric heater: https://www.walmart.com/ip/Milkhouse-DQ1001-Deluxe-Portable-Utility-Heater-1300-1500-W/136517959
Mine is a selectable 1300/1500 watt or fan only with thermostatic control. The thermostat is crap and heater was short cycling so my solution was a remote thermostat similar to this one: http://www.morelectricheating.com/d...MI_76p0-773QIVUL7ACh2ALwZHEAQYBCABEgLLn_D_BwE
If I were you, I'd definitely seal and cover the concrete floor. Concrete is a big heat sink and wicks moisture.
Laying down a sheet of heavy plastic and cover with some foam insul-board or similar and cover that with plywood (I'd recommend 3/4") would mitigate a lot of this.


----------



## ThinWoodsman (Oct 10, 2018)

The concrete pad and the barn were built long before I acquired the property. The cost of building the shop already exceeded what I had planned to spend - the insulation and the 3-phase subsystem ate up quite a chunk of change, and lumber has gotten pretty expensive. Ripping out and pouring a new concrete pad would have cost far too much.

I've been looking at putting those interlocking rubber pads on the floor; wouldn't be too much trouble to run sheets of plastic underneath. The machines would still be on the bare concrete, which is why I don't want to seal it - the moisture would just channel up under the machines or in the walls.

Re: the condensation management post, I've been looking at getting some heating pads (the ones used for auto engines and such during winter) for the machines. Sounds like that is the way the to go, and it wouldn't be too difficult to cobble together a humidity control. Really a good idea.


----------



## Dabbler (Oct 10, 2018)

Too bad it is way too cold here to grow Red River Gum - I live in the Great White North!


----------



## ThinWoodsman (Nov 23, 2018)

I chucked a $40 Pelonis radiant oil heater in the shop and have left it running at the lowest setting. Keeps the shop at 50, which is warmer than I need, without a noticeable increase in power use (~15 kWh).

The past couple of days have been the real test: lows of 3 F overnight two nights in a row, highs of 13 F during the day, and a 6-hour power outage on the coldest night. 

After the power came back on, I went to the barn to check out the shop: temperature was in the 40s despite the lack of heat. A bottle of water left on the floor as a cheap/lazy experiment has not frozen. So the insulation works pretty well, and maintaining a resonable temperature is not a problem.

I didn't get to empirically determine which devices or substances cannot be exposed to sub-freezing temps, but I'm happy with the outcome. The shop can be fully utilized in winter, as long as I can dig out the barn doors.


----------



## Boswell (Nov 23, 2018)

ThinWoodsman said:


> I chucked a $40 Pelonis radiant oil heater in the shop and have left it running at the lowest setting


This is exactly what I do. I have a relatively small insulated shop and I stash the oil heater between the wall and the lathe where it is out of the way. on the lowest setting, keeps the shop very acceptable.


----------



## Downunder Bob (Nov 24, 2018)

Dabbler said:


> Too bad it is way too cold here to grow Red River Gum - I live in the Great White North!


Yes i know what its like up there. We have friends in Calgary, they were here visiting just a couple of months ago. You could try snow gum.


----------



## Downunder Bob (Nov 24, 2018)

ThinWoodsman said:


> I chucked a $40 Pelonis radiant oil heater in the shop and have left it running at the lowest setting. Keeps the shop at 50, which is warmer than I need, without a noticeable increase in power use (~15 kWh).
> 
> The past couple of days have been the real test: lows of 3 F overnight two nights in a row, highs of 13 F during the day, and a 6-hour power outage on the coldest night.
> 
> ...



If your barn doors are being snowed in you could cut a normal sized door in one of them and make it a couple of feet off the ground so you wouldn't have to do all that digging.


----------



## ThinWoodsman (Feb 16, 2019)

Downunder Bob said:


> If your barn doors are being snowed in you could cut a normal sized door in one of them and make it a couple of feet off the ground so you wouldn't have to do all that digging.



I have an exterior staircase to the loft that provides perfect cover for a door beneath the landing. I considered cutting a door there but decided to wait and see if it was necessary. So far, the work I did on the barn roof and walls caused enough heat to be trapped that there isn't much buildup around the doors themselves. 

Now I only have to dig through the berm left by the plow guy


----------



## Toolmaker51 (Dec 24, 2021)

NortonDommi said:


> That friend I gave the heater to I also delivered several truck loads of off-cuts from a wood supply company.  These were 4" x 2" of assorted small lengths when timber was cut to length and any blemishes removed.  I thought I was supplying firewood but he used them to lay down a Parquet floor over the concrete slab, all except for an area where stuff like bulldozers or other vehicles go to be worked on.  Glue was the only cost and it is great insulation, very hard wearing too.


Floors, a favorite topic of mine.
The greatest shop flooring possible is what some term Parquet. That is wood,  grain laid horizontally, the alternating criss-cross pattern is more an efficient use of small materials. 
Not the worst, but not what I consider ultimate; good photos of early shops show how widely accepted the alternative was.
That goes by a few names, but 'wood bricks' is one; difference is they are installed _vertically, _exposing  endgrain, usually mix of 2x4, 4x4, and 2x6. 8's or 10's can be used, but more prone to cupping, being material closer to middle of timber I suppose. Nothing but radial arm or miter saw and a maul with a fair sized head. Depending on your underlayment or slab, a drum floor sander will even things up. 
Too early for posting shop pics but machines are in place. I'll frame around them and start in one corner.
Heat sources, another topic worth consideration.
Here in the Midwest, close to exact center of USA, we don't have long severe winters, there are short intense periods. My building is about 125 years old, former factory building with foot thick red brick walls, fairly thick cement floor, above grade (loading dock high), all windows are glass block, leaving only the doors to improve. Learning where roof leaked from rain, turned into weather science complete with frozen buckets of water. 
Season after season went by while looking into varied heat sources, with this conclusion. In our zone, the only reasonable source for spaces containing machinery is radiant heat. Infrared is one, some fuel burners are, but anything blowing is not. Forcing air causes it to rise, without changing  temperature of machinery. That iron is a temperature energy storage mass, that only radiant can alter effectively.
This space will be natural gas hot water boiler and cast iron radiators, at around 350k BTU, once ceiling trusses are enclosed, and blowing mountains of insulation.


----------



## Bob Korves (Dec 24, 2021)

Move the shop to a warmer climate.  Our family left Pipestone, Minnesota for Sacramento, California when I was a 8 year old boy.  Best thing that happened to me in my life.  I loved snow, winter backpacking, cross country skiing, downhill skiing, and other winter sports during my school years and later here in Sacramento, but drove up to the Sierra Nevada mountains for a day, weekend, or a week enjoying winter, then drove back to Sacramento, where it might go a couple degrees below freezing over-nite on a few nights in an entire winter.  My shops here have not needed heat to keep them warm, just an old jacket on the coldest days here...


----------



## Toolmaker51 (Dec 25, 2021)

Bob Korves said:


> Move the shop to a warmer climate.  Our family left Pipestone, Minnesota for Sacramento, California.............<snipped>


Uhh no. 
I was a CA resident until 2005. Until, that is deciding a building was now a requirement. 
I bought freestanding 6500 square feet, foot thick brick walls, loading dock high, 3 bay doors, 16' ceiling, zoned M1, dropped the flat roof and replaced with 65' 4:1 trusses and 50 year shingles, on a 85' x 160' lot; for what 6-1/2 years of _rent_ (calculated at that current per square foot rate) would have been there in Los Angeles County.


----------



## slow-poke (Dec 25, 2021)

In our old house (Mississauga )I did not have enough space in the basement so the mill was in the attached insulated garage. The garage would rarely get below freezing. I had a 100A service so I rigged up a bunch of baseboard heaters and would turn them on a couple of hours before working, worked okay, electricity was expensive. Tools had a tendency to rust because of the up and down temperature swings. I found throwing those silica packs that get shipped with so many things these days into the tool box drawers helped.

New old hose now with really big basement so everything is now in the basement shop.


----------

