cleaning cast iron saw table

[pedrod316]

what is the best way to get a cast iron saw table free from dirt/rust etc ?

try’d fertan rust converter - complete waste of time

 

[Orraloon]

I guess it depends just how rusty it is. If its just surface rust then sanding by hand and using WD40, turps or some light oil as lube. Wipe the brown slurry off with paper towel. Keep going until you have it clean and shiny. Then some wax polish to keep it rust free. The main aim is to keep it flat so avoid having at it with a power sander and scooping out hollows. Google should have tips also.
Regards
John

 

[marcros]

I would use a window scraper https://www.toolstation.com/shop/Painti ... per/p53477 and some form of light oil. I am not a huge fan od wd40 but it works well for this.

 

[Orraloon]

Those scrapers do work well as a prep before the sanding and can save a bit of elbow grease.
Regards
John

 

[shed9]

Scrapers are perfect to remove and prep. It's quite common to fit an abrasive pad (like scotch brite) to a power sander and do the bulk of the work that way. It's never going to remove metal, just the detritus on the surface. This can then be followed by very light sanding with oil. I'd recommend against WD-40 myself and opt for as light an oil as you have or can get. WD-40 is not an oil really, it's a water dispersant (hence the WD) and the carrier chemicals are irritants in my opinion.

I'd also suggest a paste wax to protect the new surface. I used to be a fan of T-9 until I read the safety sheet!!!!!!!

It's actually quite surprising how much of a difference can be made to most surfaces, even the ones that look beyond saving.

 

[novocaine]

wd-40 is an oil and a lubricant (not a long term one as it gases off quickly), it's nonane through undecane (c9-c11) and fish oil as a binder along with a solvant carrier. it's about as light of an oil as you can get, any lighter hydrocarbon is pretty much a gas or to light to be of use as a lubricant. it has a dynamic CoF of 0.11 to 0.15 dependent of force applied (for the litium grease is around 0.1 ish).

for this application, all you want is a carrier for the oxide, WD40 is perfect for it.


all aerosol oils are considered as harmful due to particle size.

(note: sorry I get really annoyed when people say WD40 isn't an oil, it is, it's about 70% liquid hydrocarbons. There was a big speel a few years ago about it by a competitor who wanted to market a new product that was "better" than it, they put more money in to their campaign and did a wonderful job of trashing the name, it is slowly coming back to being seen as a good product, assuming it's used in the right place). it isn't the perfect lubricant, it doesn't stick around long because it's so light, the heavier elements stick around a bit longer but still not great, but for short duration lubrication it is fine (like pulling a thread).

oh and all oils are hydrophobic and would work as a water dispersant, it's what oil does.

 

[Geoff_S]

I didn't know there had ever been an issue with WD40!

When I read the original question, I immediately thought of WD40 and wire wool. It has worked for me in the past. I have also used wet & dry then
finished with WD40 and wire wool.

Every time I fit a router bit, a squirt of WD40. Any screw to metal. a squirt of WD40. Any packed away tools, a squirt of WD40. Any sticky lock, a squirt of WD40.

I don't really care what it is, I will always have a can of WD40.

Anyway .... rusty metal .... WD40 & wire wool. Works for me 8)

 

[shed9]

wd-40 is an oil and a lubricant (not a long term one as it gases off quickly), it's nonane through undecane (c9-c11) and fish oil as a binder along with a solvant carrier.

No fish oil in WD40 I'm afraid, appreciate the old story of someone recognising the properties of fish oil on boat decks leading to the development of WD-40 but it doesn't contain fish oil. The actual full component ingredient list is not published beyond the MSDS risks.

I would also reiterate it is not an oil, it has some of the properties of a lubricant and you could argue most oils are lubricants but that doesn't necessarily make a lubricant an oil.

 

[novocaine]

You're right there, apologies for that slip up. everything else is correct though, it's still light hydrocarbons an organic carrier and CO2 as a propellent (because butane wouldn't be a good idea apparently) and something that isn't flammable in there too as a "binding agent/antifoaming agent" that isn't fish oil, honest, but we can't tell you what it is, oh and it's got naptha in, but we only tell the Germans that (guess what the longer lasting film is?).

and I'll stand by and say it is a lubricant, when it was sold originally it was used as a coating on fuel tanks, but also as an aircraft lubricant, as used by many companies at the time. light enough to not attached dust but with a CoF suitable for metal on metal friction reduction and a viscosity low enough to get between then unlike many other heavier oils.

ah well, there are bigger worries than if it is or isn't so I'll stand down and let you be. have a nice day.

bit more, the EU and the UK have changed it to SDS now. because they are annoying as hell. there is also a TDS for it thanks to America.

 

[Phil Pascoe]

White spirit and 40 grit on a half sheet sander will shift the crud quickly enough.

 

[shed9]

You're right there, apologies for that slip up. everything else is correct though, it's still light hydrocarbons an organic carrier and CO2 as a propellent (because butane wouldn't be a good idea apparently) and something that isn't flammable in there too as a "binding agent/antifoaming agent" that isn't fish oil, honest, but we can't tell you what it is, oh and it's got naptha in, but we only tell the Germans that (guess what the longer lasting film is?).

No problems... wasn't trying to be antagonistic in my response, just aware WD40 can divide opinion is all.

Worrying isn't it when they can choose to disclose what chemicals to own up to in a popular aerosol lube? I'm not totally against the product, I've used it in it's liquid form as a flood coolant for milling in the past (worked quite well) but find the spray version an irritant for me.

 

[novocaine]

it is rather, but no more so than not needing to disclose whats in your food, like polydimethylsiloxane, that is in so many things it isn't funny.

interesting that you are irritated by it, I wonder what it is that causes it, I know a few people that have developed reactions to certain oils over time thanks to exposure (me included but not respiratory). is it just WD or have you found it with other spray lubes? 3 in 1 stuff claims similar composition but I believe it has the afformentioned stuff in it (yes the same as in oven chips, hateful things)

hope you don't take my responses as antagonistic either, certainly not intended and it is an interesting discussion to have.

 

[Geoff_S]

White spirit and 40 grit on a half sheet sander will shift the crud quickly enough.

An interesting idea. Doesn't it make the half sheet paper soggy, or are you using wet & dry?

 

[Phil Pascoe]

As long as you don't go nuts with the white spirit and keep using it to wipe the table clean as you go, the job's done before the paper saturates. I did my bandsaw table as it had picked up a bit of surface rust - it smoothed the machining a little so made it smoother to use, as well. 40 grit sounds coarse, but over half a sheet it doesn't scratch.

 

[wallace]

Stanley blade in a holder can shave the rust off, wire wheel in a drill, green scotch bright on a ROS, then clean with brake cleaner and finish off with wax/boesheild/oil whatever floats your boat

 

[ED65]

what is the best way to get a cast iron saw table free from dirt/rust etc ?

try’d fertan rust converter - complete waste of time

As many others have already recommended a lot, scrape the worst off before you break out the abrasives, you'll do yourself a massive favour. Ten seconds of scraping can equate to about five minutes of sanding. Single-edge razors or a Stanley-knife blade both work well for this and if you're super stingy you can resharpen either multiple times.

After that rubbing with Garryflex blocks, nylon pads, coarse steel wool lubricated with anything oily (no need to get any fancier than white spirit or kerosene) will do wonders to shift what little remains. Then wipe dry and clean, then protect with whatever floats your boat, but I'd suggest paste wax is the superior choice for this sort of surface.

 

[ED65]

I'd recommend against WD-40 myself and opt for as light an oil as you have or can get. WD-40 is not an oil really...

The thing that trips people up so consistently with WD-40 I think seems to be forgetting that it's a mixture. It is an oil (obviously, we can feel it's oily) and it most definitely leaves an oily residue once the more volatile components are gone.

I'd recommend against WD-40 for this myself also, but purely because there are cheaper oily liquids in any workshop.

...it's a water dispersant (hence the WD)...

Displacement ;-)

 

[shed9]

...it's a water dispersant (hence the WD)...

Displacement ;-)

Six and two three's.

Technically it's a dispersant as it's the solvents in the WD40 that dissipates the water. Appreciate the D in WD represents displacement (according to the marketing bumpf) but I'm still good with dispersant. All the same thing though really.

Kerosene would be as effective as WD40 (without the unknown compounds).

 

[Gerry]

Any light oil and wire wool will quickly remove the rust. I usually just use brake fluid or failing that whatever is to hand, Even engine oil.
I have restored several old cast iron marking out tables that have been stored unprotected for over ten years like this and they come up like new with very little effort. They looked that bad initially that I expected to have to skim them on a surface grinder.

Gerry

 

[Jacob]

Oily rag is traditional.
If that's not enough; after you have brushed off any loose rust etc. paint or wipe on a thin coat of raw linseed oil.