Stopping Rust in the workshop?

I can confirm that too. I have one of the Ebac cheap dehumidifiers, and have given up emptying the tank! I drilled a hole in the wooden workshop floor (its up on brick sleeper walls) and put the drain tube through, so all the water runs to the outside world. No more coming in to find an overflowing tank!

I also recommend some background heating to keep things (and me) above the dew point. I have a s/h room-sealed wall gas heater, running on its low setting, and that keeps the chill off everything (again, including me). After about half an hour in the workshop (wood, lined with "insulation" board) I can turn off the gas heating, and my cussing and blinding at my mistakes (plus the heat output of the 1Kw motors on lathe and mill) makes enough heat to keep the place going!

Before this I had terrible damp/moisture problems for years - the roof timber and felt were so porous that the rockwool insulation just soaked rain up like a sponge, and then released it as fast as the dehumidifier could drink it! This was all cured by getting some swedish moulded and coated interlocking steel roofing sheets. Magic stuff! Though I can't recommend putting them on a roof in anything other than a dead flat calm, as they are big, and you can get blown off the roof very easily. Its also easy to dent the stuff by walking on the wrong bits when installing it, and unscrewing it and panel bashing the dents out is a time-wasting and soul-destrying pastime.....

Once finished, its fantastic - about £500 for an 18foot x 6foot lean-to shed - I mean workshop! It will outlast me, and the workshp is as dry as a bone - I don't even have to worry about the west end wall getting rain on it - the whole system beats any moisture ingess hands down, and I haven't installed ANY ventilation - but I DO open the door when doing a bit of silver soldering, or paint spraying! Cough spit cough!

Dave.

Reply to
speedy
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A big drawback would be noise - they act like echo chambers.

Reply to
Neil Ellwood

I second the comments on the value of good insulation and low level heat. Johns wood burning stove solution is particularly good because it both exits hot moisture laden air through the chimney and draws in colder relatively dry input air.

Simpler solutions are sometimes possible.

Moisture can ONLY condense on a surface if that surface is colder than the air in contact with it. This is worst case with the surrounding air saturated with water -

100% humidity,

A typical problem is a large mass of cast iron that has been cooled down by the low temperature of the night air followed by the warm humid air of the following morning. Warm air is less dense than cold air*. In the stagnant air of an unoccupied workshop, the cold mass near ground level will set up convection currents that eventually bring much of the total air volume of the workshop in passing contact with the cold mass - each time depositing its evil bit of condensation.

It's not the small bit of stagnant air around the surface that's the problem - it's the fact that the convection currents produced by the temperature gradients make it possible for a large fraction the water carried in the workshop air volume to be deposited on the cold mass.

Because of this it's possible to make a substantial difference by simply blocking the path of the convection currents. Most of my kit is in a relatively benign workshop environment but a large floor standing circular saw with a cast iron table top has to live at the end of the garage in which I park my car.

Convection currents are roughly blocked by a large plastic sheet which is draped over the whole machine. When I first installed it several years ago I "polished" the top with a coat of simoniz car wax but apart from that it's had no further treatment and it's still rust free!

I've probably been pretty lucky because it's a very old machine with a well seasoned cast iron top. The top is also less massive than the average lathe. Nevertheless the difference is substantial - quite a lot of rusting is evident on unprotected mild steel stocks originally lightly greased and stored in the same environment.

It's not a method that I would rely on for the sole protection of a newly bought expensive machine but it's a simple and effective second line of defence. The thing to remember is that the main convective flow is vertically downwards so, as long as your plastic sheet deflects this, you're winning.

Jim

  • Water vapour is less dense than air so the larger fraction of water in the warm humid air increases the density differential.
Reply to
pentagrid

We have stored machinery up at a friend's farm (what would we do without friends!) and each has a piece of truck grade pvc/nylon sheeting over it. That has kept things nice over the past year or so without any heating at all. The building is ventilated (broken windows etc) but the roof is dry.

The stuff that has to sit outdoors is usually multi-wrapped in various sheets but the PVC/Nylon that is used for truck sheets etc is the last one on and is totally waterproof. The polypropylene woven blue tarps are next to useless, especially after a decent bit of wind (natural, not bean-induced!)

Peter

Reply to
Peter A Forbes

Gawd!! Don't let 'em know on RCM or we'll have 45 replies about how you won't last a month if you breathe the spray from anything Better get an extraction system straight away. (PS I wouldn't mention mercury either)

----------------------------------------------------------------------------------------------------- snipped-for-privacy@boltblue.com John Lloyd - Cymru/Wales

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Reply to
John.LloydUNSPAM

In article , snipped-for-privacy@cwcom.net writes

LOL! Yes, they do seem a little prone to worry over there, don't they?

It's amazing they ever get anything built.

Oh... Wait... ;^)

Reply to
Nigel Eaton

How can they, they don't have time. They are that busy telling you how they have 200,000 miles on this li'lle ole pickup truck in the last three years without a blade o trouble.

[Hint divide 200,000 by 55 mph to get hours then divide this by 24, then 7 and you get 21 weeks solid driving 24 / 7 without a piss or is that what they are taking ? ]

-- Regards,

John Stevenson Nottingham, England.

Reply to
John Stevenson

In article , John Stevenson writes

They're actually allowed to go faster than 55 these days, in places.

No bloody GATSOs either!

How's Cecil? Up and about again?

Reply to
Nigel Eaton

I did know that, CA was the same as us at 70 when I was over in 99. Just using 55 as a decent average.

Cecil is still on the life support machine, or rather the computer is. All his inards are outards at the moment, wires going everywhere. New driver box is built, just needs mounting on the wall and the power supply needs mounting and wiring up. Taking the time to update a few more bits like limit switches whilst it's down. Tomorrow's out, paperwork day, but hopefully Tuesday may see him take a short breath. Also going to update the PC as well, been running for years on a P133 and by going x10 microstepping I'm moving up to a 1.0G PC to keep the step rates up. Better not say too much here about this because PC's can't run steppers, or so I've been told Good job no-one told Cecil otherwise he might have thrown a fit before, he's only had this PC for about 6 years and it's never missed a beat.

-- Regards,

John Stevenson Nottingham, England.

Reply to
John Stevenson

What does this mean for my rings, John ?

Cheers Tim

Reply to
Tim Leech

Tsk tsk! Surely you're not suggesting that any engineer worth his salt would consider wasting valuable workshop space by cluttering it up with cars? (other than the one being dismantled/reassembled, of course...)

Regards, Tony

Reply to
Tony Jeffree

snip

Reply to
Dick Ganderton

In article , Dick Ganderton writes

Bloody hell, don't tell me the plague's spreading? I know they have red-light cameras, but I didn't think the curse of the Gatso had reached there.

Reply to
Nigel Eaton

snip

Reply to
Dick Ganderton

Doh! lost the plot - just how did we get from rust in the workshop, to de-humidifier, to dewpoint, to GATSO's in California?

Puzzled!

Steve

Reply to
Steve

In article , Steve writes

Welcome to Usenet. Great, innit?

Reply to
Nigel Eaton

Ventilation certainly makes a big difference, especially where there is damp penetrating from outside. My workshop is in a cellar room - built in 1900 so the DPC is bricks laid directly on sandy soil. The damp doesn't just rise, it goes sideways and down as well ;-)

Fixing the problem involved 2 approaches:

first, reduce damp penetration by painting the walls with an Epoxy

2-part paint (a water based epoxy that will cure on damp surfaces).

second, install forced air ventilation. I used a unit that Wickes used to sell - two centrifugal fans, one to expel air to the outside, the other to draw fresh air in. Both air flows go through a heat exchanger to use the (warm) exhaust air to warm the incoming cold air. Has a built in drain to lose the inevitable condensate in the exchanger.

The result is a very dry cellar - no rust on tools etc. and no "musty" cellar smell either, unless you switch off the ventilation system.

Regards, Tony

Reply to
Tony Jeffree

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