I live in Minnesota where the winters are cold. It's not unusual to be 10 degrees or colder for a couple weeks or more. Someone told me that it would be a bad idea to have my lathe in an unheated shop during the winter and using it wouldn't be such a good idea while it's cold. I am concerned about possible damage. Do you all share this opinion?
I am now in the process of finishing my shop and am in need of advice on the type of heater to use. The debate is between a normal ceiling-mounted natural gas blow-air-and-dust-all-over-the-place furnace or a ceiling-mounted tube-style radiant heater. I think I need around 60,000 BTU/H. I can find a decent forced air for around $600 and the radiant style for over a $1000. Does anyone know anything about either of these? Is one more efficient than the other? Any idea on operational costs?
I saw a machine that was stored in an unheated hanger. It was prefect when it went in and after a few months (give or take) it had lots of rust. A lot of this could have been prevented just by spraying the machine surfaces with LPS-3.
I also stored a lathe in a garage covered with plastic and coated with LPS-3 for over a year without any noticable rust. I have since learned that a breathable fabric makes a better cover because it will let the moisture out.
I have been told that applying a small amount of heat such as a light bulb in the base of the machine keeps it just enough warmer than the surrounding air to prevent moisture buildup.
Someone here stated that fans to keep the air moving help in damp enviroments.
If the heat will not be on constantly I would do the following.
1) Forced air heat to heat the shop up reasonably quickly.
2) Radiant heat over the lathe to make a comfortable work area.
3) Rubber matt on the floor to isolate your feet from the cold floor.
4) Light bulb in the cabinet of the lathe to drive out moisture.
5) Coat with oil for short periods of inactivity
6) coat with LPS-3 for long periods of inactivity
7) cover the machine if exposedd to dirt or abrasive dust from other shop activites.
8) You might find it necessary to run the machine for a while before using it in the winter.
I believe that the issue is condensation. If you heat your lathe, moisture won't condense on it. So, I vote for it does not matter how you heat it. You can put a tarp over it and a lught bulb underneath the tarp. They sell special temperature controlled switches not too expensively, also.
Although you didn't mention how large your shop is if it's about the size of a single car garage I'd suggest the following: Tent the lathe with heavy plastic and slip one of those thermostat controled oil filled heaters underneath. You should be able to keep the lathe at any temperature you wish and the heat that excapes should keep everything else from freezing. If your shop is well insulated add another heater with a timer in another area of the shop set to turn on an hour or two before you plan on working. If the shop isn't well insulated adding a cealing mounted, gas fired, radiant heater will probably give you the best coverage if you're sure you won't use a forced air system. Anything would be better than a customer who needed to warm-up his door machine, threw a tarp over it, set a small fire under it, and walked away for a moment......!! Lucky he didn't burn the whole place down.
My old buddy (long since deceased) had his small lathe in an unheated log cabin garage located about 2 miles from Twig Minnesota. For those of you not in the know, this is one of theose places that vies for the "coldest temp in the 48 states" places. A light slathering of oil, it ran that way for years.
The big things to watch:
1) Make sure that any lubes are still working. Some greases will set up solid at the 0 f and below range. (30 weight oil turns to a solid around
-25 F or so)
2) Make sure there is no source of moisture to cause condensation. Uninsulated steel pole barn roofs and kerosene bullet heaters are big culprits. I used a bullet heater extensively one winter, no problem on the things in the area I heated, stuff in the cold corners got quite rusty.
3) Get a cloth tarp (NOT PLASTIC!) big enough to go over the machine and touch the floor all around. Put a 40 watt bulb on the chip pan under the headstock.
4) You won't be able to do precision work until the machine warms up to room temp. there is enough drag and drift to mess things up.
5) If you are working on a project (eg old car), you need the forced air to warm the entire area to something reasonable, say 50 degrees. If you are just working at the lathe, the tube style radiant heaters are nice.
6) Stay away from the open grid radiant heaters if you are worried about rust. The put too much moisture into the air, it condenses on any unheated metal.
For a random use shop, I think I'd get a ceiling mount forced air unit. Try and find a wall thermostat with good controls down to 30 degrees. (Regular units stop at 50 degrees or so). Let the heater run, keep the temp at 35 degrees. Just enough to keep the floor from freezing down.
If you want to be cheap, I see a lot of used 80% efficient 75k BTU furnaces that are take outs for higher effiency units. Going price is $20 to $75 or so.
My lathe lives in an un heated garage and shares with two cars. Both cars come in wet in the winter. Winter temp does not fall below 32°F much, but I am on the water so damp is my main problem.
I have a 'boat' top canvas cover that snaps over the lathe. Very easy to get on and off. Two, 60 watt light bulbs live and are on ,24/7 on the chiptray under the bed. This has worked for me for the last ten years. Lathe is used most weeks and is lightly oiled after each use and clean up.
I have the same problem in the winter but also the reverse in the summer. My shop is 400 sq. ft and the humidity of the summer also causes rust to form on my tools. I am looking for a heat and cool combo unit to fit in the window. Any suggestions on that? Um yes,...I'm cheap. Rather spend the $ on tools.
LPS3 does a pretty good job of protecting stuff from rust. I use it a lot. Way oil also does a good job, at least on horizontal surfaces.
I don't like the idea of leaving a light bulb or heater under a tarp unattended. It seems like a fire hazard.
Go to your local Goodwill or equivalent and buy some used sheets. Covering your machines with them will help a lot. They minimize air flow (so you don't get all the condensation in the room, just that under the sheet). They also breathe and are cheap.
Is the room you're talking about heating so large that you need a forced air furnace? Get a convection furnace, you can always add a table top fan if you need forced circulation.
Steve Brownfield, Ma>I live in Minnesota where the winters are cold. It's not unusual to be 10
I have a ceiling mounted natural gas forced-air unit heater in my shop near Minneapolis. Been using it for years. I like it! It doesn't blow dust around; warm air velocity is pretty low by the time it reaches work surfaces or the floor. I also have a slow-turning fan mounted high and aimed straight down. It helps prevent stratification with much warmer air near the ceiling (roof) rather than down where it's needed.
If you let your machines get cold, even down to 40, they can get stiff to operate. It takes several hours for a cold lathe or mill to warm up.
If you are interested in heating the shop, and not just the machine, I would recommend radinat heat. We put in a radiant system after years of ceiling mounted forced air units. The difference was amazing. All of the stuff gets warm, not just the air. Also, you don't need to keep the shop at 70 deg, just enough to either keep above the dew point, or for your own comfort.
Nothing will cause your machines to condense moisture faster than rapidly changing the temperature in the shop. The mass of machine tools makes them slow to warm, so the moment you raise the ambient temperature, they begin condensing any moisture contained in the air. You'd be far better off to keep your shop at a constant temperature, even if it's not very warm, than to economize by heating only the machines, which won't be all that much warmer than the surroundings without considerable heat introduced.
Regards comfort, I'd be inclined to suggest a forced air unit, but only if you can get some duct work down around the floor. My previous shop had nothing but overhead ducts, so the floor, and my feet, never really warmed up. I lived in Utah at that time, where winters are severe, but nothing like yours. I don't like cold feet, and heating the floor is most difficult. So much so that I have hydronic heat in my current shop, which keeps my feet warm. If they're warm, I am. Avoid electric heat if possible, and oil. I'm stuck with it (oil) and the price has more than doubled in the past year. Sigh! It's going to be a cool winter in the shop, I fear. :-(
If I had it to do over again, I'd install a ceiling fan in the old shop, but it, like us, is long gone now----in fact, it's the dining room of the bed & breakfast the old place became. I'm giving some thought to doing it here, however. With our 12' ceilings, it's much hotter on top than it is on the bottom, even with hydronic heat. I get the idea I'm tossing a considerable amount of my heat into the attic as a result, even though I have R40 insulation. Thanks for the tip, Don.
Is a wood stove a reasonable option for you? I frequently use mine for annealing and heat treating steel. The flame-cut hot-rolled steel cutoffs that I have bought cheaply have hard spots along the cut line and near the outer edge of the original plate. The stuff is much easier to machine if I soap it up and heat it in the stove to a low red. Annealing makes cold-rolled round stock turn better, too.
The wood stove doesn't work well as a blacksmithing forge. Does anyone know of a gas forge or heat-treating oven that will also heat a home safely and efficiently?
I appreciate all the info that you guys have given. They all sound like great options.
I have two shops I am going to be heating. The one is a three-car garage that is about 35 x 25. The other is a polebarn that is 24 x 52 but I am planning on refurbishing that building with new sheetmetal and doors this coming spring. In the meantime, I have plans to finish off the three-car garage (I'm in the wiring process now) and would like to keep my lathe there until the polebarn is done. I have plenty of projects to keep me busy all winter long so I would like to have it comfortable enough to work in without wearing my artic-gear Carhartts and snow boots.
My dad gave me a number of a guy that is selling out his auto repair business. He has four 100,000 BTU/H U-tube style radiant heaters, 18 feet long. He said he paid $2,100 each and he is selling them for $750 each. I am considering buying two of them - one for the garage and one for the polebarn when I get it fixed up. The polebarn has fuel oil heat in it now and I'm not excited about that at all; not when natural gas is an option.
A thin layer of soap reduces scaling considerably, at least in the mostly reducing atmosphere of the bottom of my stove. Ivory works well. After quenching in water the steel surface is light grey instead of the usual black. A forming tool hardened this way can be sharpened to cut steel with only a whetstone, which means that the machined edge stayed pretty sharp and didn't lose carbon. Usually I don't take a chance, though, and wrap the tool in stainless heat-treat foil with powdered charcoal. Paper is also supposed to work. Before I found the foil I used tin cans or iron pipe scraps.
Large chunks left in for hours and probably exposed to more oxygen when I feed the fire or let it burn out have a thin coat of brittle reddish scale.