Workshop heating

[RayW]

At present, my workshop, which is built of concrete blocks, is uninsulated and unheated. As a result, in the colder weather, I do get some problems with surface rust on metal surfaces, in particular, the lathe and mill table. I usually prevent this by coating everything liberally with WD40 or oil when they are not in use.
Just recently, my recently completed Sphinx engine was left in the workshop for several nights, and, although wrapped up well in plastic, i still found that the exposed end of the cylinder liner and the flywheel faces had begun to rust. For the time being, I have carried the engine indoors, but once it is mounted on a trolley with cooling tank, etc, it will be much too heavy to lift and will have to stay in the workshop.
I am, therefore, going to have to look at some sort of low level heating to prevent condensation. I currently have a fan heater, but just wondering if a tubular heater of the type used in greenhouses would do the job. I would be interested to hear what heating methods other members use.
P.S. Unfortunately, insulation of the walls would not be a practical proposition as the only way that could be done would be to totally empty the workshop. The floor, incidentally, is concrete covered with interlocking rubber tiles.

[Admiral_dk]

I did ALL the insulation on my house on the outside !!!

First year after I bought it, I had an excavator do a trench all the way around the concrete foundation, down to aprox. 10-15cm. (4-6") below floor level in the basement (where the workshop is) and added some 200mm (8") of polystyrene insulation batts (water proof) onto the 'wall' with expanding foam filling the gaps (careful here) and 20mm (0.8") sheets off 'concrete-board'. Next was a thin layer off gravel in the bottom of the ditch - a drainage pipe (the 'holed flexible plastic tube' type) and 60cm (2') more gravel followed with sand up to 10cm (4") from the normal ground level and dirt + grass turf on top.

The following year I did the rest of the outside walls up to the roof. As it was a 'wood beam' build house - I put a strong 'framework' made from wood on the outside, that had exactly the same space between them as the with off the Rockwool batts (they didn't need to withstand water) followed by a 'windbreaker' layer of tar paper and vertical wood planks as the outside. As the ceiling already had 350mm (22") layer off Rockwool when I bought it - that was that.

Honestly, it did not do much to the heating bill, but it still improved the inside climate quite a bit as ALL cold-spots disappeared completely + the air moisture dropped from 70-80% to 30-40% in the basement => rust problem went away too 

Two years later I changed ALL electric heating out with (externally produced at the waste cinerating plant) central heating and saved a bundle on the bill    So the workshop is the hottest place in the house in the winter after this @ around 20C ~ 68F and almost better - it is the same temp in hot summers 

I can't tell you if you could do something similar or not ....

Best wishes

Per

[scc]

My workshop is brick built with no cavity (1840) I lined it with 1 inch thick polystyrene straight to the brick with "no nails". Ceiling panels were screwed to joists. It has all been left bare apart from bench backs, etc The roof externally is 1inch ply covered with steel box profile, windows are double glazed and the door is 2 1inch ply panels screwed together. floor is original flags straight on the soil! I get no rust problems. Heating is a small fan heater run for ten minutes before I start and turned off when I do.  It was cheap and simple to do. Pics are on "garden workshop " thread if anyone is interested.   I appreciate this could be awkward if you already have benches,etc fixed to walls.           Terry

[steamer]

I use a direct vent natural gas heater.  It has  a LOT of capacity...The walls are wood stud un-insulated.      To improve this situation, I added the tufted mylar sheet insulation to the shop walls.   It's put on over the sheet rock with a staple gun, and they claim it's R9..  (equivalent to 9" of fiberglass batten)...it improved things very much.

Dave

[kvom]

My shop is wood frame with fiberglass insulation in walls and ceiling.  Heat is radiant from Pex tubes imbedded in the slab circulating hot water.  Very pleasant to work in the winter and I've never had rust issues.  Of course, for heat like this you need to plan before building.

[Jo]

How about putting the model in an air tight box or large polythene bag with silicon gel inside to absorb/remove the moisture?

My old workshop was in a concrete sectional garage. Nothing I did kept down the moisture/rust problem.

Jo

[GordonL]

One thing I found was to avoid the unvented infrared gas heaters. They put a lot of moisture into the air. It sounds good that you are not sending any of the heat up the chimney but burning gas creates water. The portable units work good for short term temporary heating but are not a good permanent solution. 

[steamer]

One thing I found was to avoid the unvented infrared gas heaters. They put a lot of moisture into the air. It sounds good that you are not sending any of the heat up the chimney but burning gas creates water. The portable units work good for short term temporary heating but are not a good permanent solution.

Don't have that problem....direct vent gas heater....combustion is totally separate from the volume of the shop....so quite dry.
Dave

[Rick Doane]

'in the winter after this @ around 20C ~ 68F and almost better - it is the same temp in hot summers  "

I too have that luxury Mr. Per.  Also, I have found that maintaining the temperature results in more accurate measuring, machining, and fitting of critical moving parts.  It is not uncommon to have differences of .00008 - .0001 over a 5-10 degree F variable.

Rick

[awake]

Ray, where are you located? Local climate could have an impact on the best approach to take.

With regard to putting the model (or anything else) in a sealed plastic environment - I have always heard that this is not the best approach. The problem is not whether or not air can get to the model; the problem is whether or not moisture is condensed from the air, particularly for rapid temperature changes. Sealing the model in a plastic bag means the moisture cannot "breathe" away; it has no place to go except to condense on the model.

Of course, if you could fill the bag with *totally dry* air, and seal it, you should avoid most problems. Alternately, you could fill the bag with inert gas (e.g. argon, if you've a TIG welder on hand).

Failing all of that, I have seen two ultra-low-tech approaches. One is an incandescent light bulb positioned strategically to provide a bit of warmth - inside a lathe cabinet, or something like that. Of course, these days (at least here in the US), it is hard to find an incandescent light bulb any more, and CFLs and LEDs do not generate near as much heat. But if you go with this approach, be sure there is no chance of anything combustible coming into contact with the bulb!!

The other option I've seen is a bit surprising, but apparently it works: keeping a box fan (or any sort of fan, I suppose) blowing on the tools that need to stay rust-free. Apparently this helps to keep condensation from settling on the tools, and maybe it also helps to even out the temperature swings - ?

A somewhat higher-tech approach is to use LPS-3 or Boeshield or similar rust inhibitor. Note that WD-40 is great for many things, but it is very, very poor as a long-term rust inhibitor. The downside with these is that they leave a noticeable film, which will have to be removed (using WD-40 or similar!) before using the tool. On a model engine, you would only need to remove it from parts that slide together ... but there I'm not sure how any of these products interact with heat.

A final thought that you likely already have considered, but just in case: be sure there is nothing in the atmosphere that is accelerating rust. One possibility would be salt, if you live near the coast; in that case, your best bet is to insulate and seal the shop as much as possible, and maintain a controlled environment using something like a mini-split HVAC unit. But there is another possibility that sometimes catches people by surprise: be sure there is no muriatic acid or anything of that sort stored in the same space. An open container of that stuff can rust an entire shop overnight. A closed container works more slowly, but it is very hard to prevent some escape of the corrosive gas. I have some muriatic acid on hand, but I keep it stored outside in a shady spot, in a covered 5-gallon container, well away from anything rust-able.

[RayW]

Thank you all for your helpful responses. Jo's suggestion of a sealed box to enclose the engine is basically what I did with my Stuart Half horsepower, where a large wooden box attaches to the wooden platform on which the engine and cooling tank are mounted with four snap catches. This has proved quite effective and would probably have been even more so had I enclosed a moisture absorbent trap inside.

One other suggestion I have come across is to protect the unpainted surfaces on the engine either with clear lacquer or with Renaissance wax, which is a special protective wax developed, I believe, by the British Museum, to protect valuable artefacts. I have ordered a small tin of this to give it a try. The main vulnerable areas are the unpainted flywheel rims and the exposed end of the cylinder liner,

Unfortunately, other options, such as insulation of the workshop, would involve major upheaval, not to say expense, and would not be practical unless I was completely gutting and re-organising the whole shop as there are benches and cupboards attached to most walls.

[tangler]

Hi Ray

I use a pair of 80W Dimplex tube heaters from Screwfix.  These have built in thermostats and I have mine set to maintain the minimum temperature to 10 degrees  C. However, my garage does also have 50mm of Kingspan insulation.  One option you might consider is a desiccant type de-humidifier, these will work at low temperature.  Not only do they dry air, they also pump out a bit of heat.  Have a look at the Meaco DD8L JUNIOR.

HTH,
ROD

[Flyboy Jim]

Ray............would a portable dehumidifier be an option?

Also, sometimes the expense and time of doing a "major upheaval" is well worth it in the long run, depending on how long you invision using this space for your shop.

Jim

[Chipswitheverything]

I have a limited amount of insulation built into the inner walls of my workshop, but no normal heating system to trickle heat the place.  In cold and damp weather I run a small dehumidifier and keep the door shut as far as possible, and that seems to give pretty effective control of rust and dampness.  I do keep the larger machines covered with plastic sheet and blankets over that, a bit of a nuisance but mostly it's too cold to do much in there during the winter!  Dave

[ChuckKey]

I use a dehumidifier in my shop, which currently has exposed roof trusses and Tyvek under the tiles, and is awaiting an insulated ceiling and possibly a replacement for the roller shutter door. I don't have a handy drain so, with the wet autumn we have had in the UK, the 4-Litre tank is full every morning. It mostly holds the humidity below 70%. I would like it lower, but the place is just too draughty ATM.