CITRIC ACID DERUSTING FOR A BEGINNER

[sjp001]

Personally I'd either just stick it back in the citric when it comes time to paint, or run over it with a wire wheel. The products I have seen that you can apply easily to prevent flash rusting will need to be removed, so it strikes me as as much work to use these and more expensive.

 

[MattF]

ive seen por15 metal ready suggested as a product you can spray on and does what im asking ...bit too dear for my tastes so wondered if anything else left a paint friendly coating

As Screwdriver mentioned, a light wipe with Linseed Oil. Protects, and it'll overpaint fine.

 

[sjp001]

^Great advice.

 

[bigegg]

As Screwdriver mentioned, a light wipe with Linseed Oil. Protects, and it'll overpaint fine.

boiled? or raw?

 

[Screwdriver]

boiled? or raw?

Boiled linseed oil isn't really boiled, it's thinned out with turps (?) and/or other solvents to promote drying/curing.

Raw/unmolested linseed oil is a bit too thick and goopy for metalwork unless you burn it on.

 

[bigegg]

Boiled linseed oil isn't really boiled, it's thinned out with turps (?) and/or other solvents to promote drying/curing.

Raw/unmolested linseed oil is a bit too thick and goopy for metalwork unless you burn it on.

originally boiled with lead? i believe, to make it dry.
now done with synthetic drying agents.
i have a couple of gallon in the shed, somewhere...

I wasn't aware raw linseed oil was *that* thick - never used it.

All i was thinking was that a non-drying oil would overpaint more easily?


<edit> turns out raw linseed oil dries anyway - just more slowly.
linseed oil dries exothermally and can heat up enough to cause rag fires.

 

[Screwdriver]

linseed oil dries exothermally and can heat up enough to cause rag fires.

Oh yeah, that's a very important safety tip. If you scrunch up a rag wet with linseed oil, it can quite easily autocombust as it cures exothermically. I have never seen it but then again, I throw any papers onto the bonfire - NEVER IN THE BIN!! Rags I tend to lay flat or hang up somewhere so they don't have the critical density to overheat.

 

[MattF]

boiled? or raw?

I always use raw, thinned with gum turpentine. Takes longer than boiled to cure, but doesn't have the added crap they put in boiled.

 

[steveo3002]

how long does raw take to dry?

 

[Screwdriver]

how long does raw take to dry?

Depends. Longer...

 

[MattF]

how long does raw take to dry?

Varies. The thicker the coating, the longer it takes. A day or two will usually have it cured, if applied thinly.

 

[Lazurus]

Danish oil can be painted over to with most paints, similar and quick drying.

 

[steveo3002]

when do you if the solution is finished /spent ...got some grotty drum backing plates in a couple of litres , its gone dark brown and cant see the parts

 

[bigegg]

when do you if the solution is finished /spent ...got some grotty drum backing plates in a couple of litres , its gone dark brown and cant see the parts

i honestly dont know.
i suppose you could test with litmus paper?

in reality, when i notice its not working, i'll tip it out, and refill - its coming up to 8 months of use, and still working.

its not like its expensive. ten quid gives me more than enough for a 200l barrel.

 

[steveo3002]

so one mix ought to be enough to derust a pair of backing plates just submerged in the bottom of a bucket ?...been in 24 hrs now , they light rust went straight away , the pitted bits are still rough

 

[bigegg]

so one mix ought to be enough to derust a pair of backing plates just submerged in the bottom of a bucket ?...been in 24 hrs now , they light rust went straight away , the pitted bits are still rough

i would have thought so. easily!

i have about 40? litres + a kilo or so of powder in a 200l barrel, and its done about 10kg of badly rusted spanners, 20kgs of horseshoes, two big (6") engineers vices, 3 big woodworking vices, a dozen smaller vices, and a fair few other hand tools.

i put an old set of cast iron kitchen scales in on friday. gonna pull them out this afternoon, but a cursory glance shows the liquid is still working.

 

[ronan]

so one mix ought to be enough to derust a pair of backing plates just submerged in the bottom of a bucket ?...been in 24 hrs now , they light rust went straight away , the pitted bits are still rough

Take it out every so often and give it a rub of a wire brush in the heavily pitted areas.

 

[slim_boy_fat]

Well, I can confirm it doesn't clean grease and oil off stuff. A couple of pistons [c/w gudgeon pins/conrods etc still attached] I put in a couple of days ago, came out exactly the same.

So electrolysis it'll be, once I get the Ford gudgeon pins out - looks like heat and a BFH as I don't have a press or a vice with enough capacity...... [And, yes, I'm still making clocks ]

 

[PhillipM]

You can put little a bit of surfectant - cheap apc, dish liquid, etc, in the mix to help it break through light oil/contaminants.

 

[slim_boy_fat]

You can put little a bit of surfectant - cheap apc, dish liquid, etc, in the mix to help it break through light oil/contaminants.

Never thought of that [senior moment ]. I'll give it another go since it's easier than electrolysis or ultrasonic cleaner. A kettle of boiling water will go in with it.