Quantcast
  • We invite you to join UKWorkshop.
    Members can turn off viewing Ads!

Sacrificial anode for machine tools rust prevention

UKworkshop.co.uk

Help Support UKworkshop.co.uk:

minilathe22

Established Member
UKW Supporter
Joined
31 Jan 2016
Messages
294
Reaction score
25
Location
Stevenage, UK
Hi there

So I am taking delivery of a lathe soon which I will be restoring, and once I have got all the rust off the bed I want it to stay that way, I have been looking at the various common ways of doing this and I don't see any mention of using a sacrificial anode such as a block of zinc or magnesium attached to the bed. This is common I believe for underground/underwater pipes and metal boat hulls, I wonder if anyone has tried this with a cast iron machine tool before? If I bolt a piece of zinc to an unpainted part of the lathe bed, perhaps underneath, would I see it protect the top unpainted surfaces from rust completely I wonder?
 

Dee J

Established Member
Joined
24 Jan 2006
Messages
267
Reaction score
25
Location
West Devon
I think you need the whole system to be immersed in an electrolyte for it to work. Whether that's water or damp earth. Don't think air works. For sacrificial protection in air you need galvanising.
 

AES

Established Member
Joined
18 Feb 2011
Messages
4,575
Reaction score
204
Location
Switzerland, near Basel
I'd agree with the above. I'm not completely sure, but unless your lathe is immersed in water, or at least in a VERY damp hole in the earth, I don't think the sacrificial anode idea will work.

Much better to try and ensure your shop is free of damp air/condensation, etc. After de-rusting some tool finds (electrolytic, works wonders and is easy) I've had no further rust problems 'cos the stuff stays in my shop which is free of damp air.
 

minilathe22

Established Member
UKW Supporter
Joined
31 Jan 2016
Messages
294
Reaction score
25
Location
Stevenage, UK
It seems you are right and the water is part of the "system" to make it work. I guess galvanized metal works without liquid water, as the sacrifical zinc is always very close to the protected metal.
 

Rorschach

Living on borrowed time
Joined
6 Jan 2016
Messages
4,306
Reaction score
306
Location
Devon
Galvanising works because it is a coating for the most part, like paint. But unlike paint, when scratched it is still effective because it is close enough to the metal underneath to be "sacrificial" when there is water present. When the areas of wear get too big though the system breaks down and rust occurs.
 

Inspector

Nyuck, Nyuck, Nyuck!
Joined
18 Jun 2006
Messages
1,785
Reaction score
179
Location
Saskatoon, SK., Canada
The best way to prevent rust on a machine is to keep the shop it is in warm, above the dew point. Since many people don't want to / can't heat the space the next best thing is to keep the machine itself warm. A canvas cover with a rod type heater will keep it warm and toasty, preventing any moisture from condensing to form corrosion. Lee Valley as an example sell these but there are other brands at different price points to do the same. https://www.leevalley.com/en-ca/shop/tools/workshop/tool-maintenance/69378-goldenrod-dehumidifier Some brands attach directly to the metal and some heat the air just above.

Pete
 

bussy

Established Member
Joined
13 Mar 2013
Messages
128
Reaction score
2
Location
Tyneside
If your workshop is cold/unheated all you need to do is ensure you have air flow through your shop. No heating in mine but good airflow never had any problems with rust. The problem with heating is that you will need to maintain that heat as, if your shop cools overnight the moisture in the air will condense out particularly on your cast iorn surfaces,
 

clogs

just can't decide
Joined
24 Jul 2020
Messages
550
Reaction score
240
Location
Vamos, Crete, GREECE.......
My last house was a converted 17th century water mill.....everything was damp....
My workshop was a big open barn.....
all my machines were covered in an old Duvet and a blanket with a 11watt curley whirly bulb underneath...
left on 24/7..... they were on from the first time there was a nip in the air till around March.....
never notised the elec bill at all....
plus the metal working machines all used coolant.....never a problem with rust.....
also got sick of chucking out big rolls of MIG wire that went rusty over the winter....
so put a bulb holder in the welding wire compartment and covered with an old blacket ...
again never a problem...
take just a few mins to roll up and remove coverings....well worth it....
 

Myfordman

AKA 9Fingers
Joined
19 Jan 2013
Messages
2,302
Reaction score
114
Location
Southampton area
If your workshop is cold/unheated all you need to do is ensure you have air flow through your shop. No heating in mine but good airflow never had any problems with rust. The problem with heating is that you will need to maintain that heat as, if your shop cools overnight the moisture in the air will condense out particularly on your cast iorn surfaces,
As Pete said above heating the machine is the secret and ideally thermostatically controlled not to a specific temperature but to a few degrees above ambient. In that way condensation cannot form. Heating cost are therefore minimised.
 

minilathe22

Established Member
UKW Supporter
Joined
31 Jan 2016
Messages
294
Reaction score
25
Location
Stevenage, UK
I only moved recently and have found surface rust is worse than I am used to. I decided to examine the walls and floor and have discovered that on a wet day there is visible water seeping through the wall just above the damp proof membrane above the floor. I believe rainwater is running down the outside of the wall but yet to confirm as I can't get to it easily. On drier days there is nothing obvious to see. Its in one spot about 2 feet long, I hope solving this will be a big improvement!

I have seen very small self adhesive pad heaters, that way I can stick one out of the way and leave it there on some of the bigger machines.
 
Top