Solvent for degreasing engine, without damaging the paintwork?

Hi,

I have an miniature meths-fueled model steam engine that probably hasn't been run for 50 years.

The wheels won't turn as as the pistons are jammed solid, probably with gunk, solidified oil, or possibly rust.

I would like to give it a good soak to gently dissolve or soften the oil residues, but I can't risk anything damaging the original paintwork, as that would ruin it.

What solvents are suitable to do this?

I'm assuming that white-spirits and acetone will attack the paintwork, but what about isopropyl-alcohol, ethanol, or panel wipe (aka naptha?)

(Suggestions for a better technique are of course welcome.)

Thank you

Naptha for all intents and purposes is white spirit. Whilst ethanol and isopropanol may not greatly affect the paintwork, they are not great solvents for oily residues either.Of the two, my money would be on iso-propanol. Paraffin as present in WD 40 might be an answer.

Odourless white spirit might also work, it has rather less solvency than the straight version.

Chas

Hi Nicholas

If you are trying to protect as much as possible of the original paintwork, as you have suggested, I would go down the restoration route as far as possible. That is: start with the mildest possible solvent ( i.e. water ) and work up slowly from there - probably to isopropyl alcohol ( iso-propanol ). I fear that more aggressive solvents are likely to dissolve, discolour or otherwise permanently damage the paintwork. however there may be others on here who have specific experience with old steam toys who can offer more specific advice.

A cotton bud with a dab of the selected solvent in an inconspicuous location will indicate the likely effect on the paintwork of more extensive cleaning. In any event I would avoid wholesale soaking and work on a slow dismantle applying solvent to only the parts you are working to free up.

Also, beware the use of aerosols. While the solvent may be relatively benign, the hydrocarbon propellant may be very damaging to paints, plastics and rubber. I now only use solvents in hand pump spray bottles for this reason.

Best of luck with the project. It is great to see these things being brought back to life.

Pero

Thanks for the advice.

This is a conservation & restoration project, so avoiding damage is the primary concern. I'm very cautious as it is an expensive antique.

I also wonder if something like 3-in-1 penetrating oil (from a tin, not a spray can) would do a better (and safer?) job of loosening the jammed cylinders (from the inside) than a solvent?

I would soak it in paraffin, I'm pretty sure that will have no effect on the paintwork but it will soften old oil and other such stiff lubricants.

Regards Brian

Jizer or Gunk are water washable degreasers which are unlikely to damage paint.

Warming (with a hairdryer) components stuck together with very old oil will loosen them. You need keep trying to move the stuck item back and forth.

Works on old jukeboxes when the selectors freeze solid.

Hi,

Daft as it might seam how about using a thin motor oil, eg sae10, applied warm/almost hot.

This, when its soaked into the old oil can be wiped off

regards

Bernard

Have a look at some of the de-greasing and gunk-removing products used by bicycle repairers, they are very kind to paint, although most bike frames these days are powder-coated which seems to be less affected than regular paint.

Alternative that I've always used is kerosene (which may or may not be the same as paraffin suggested in an earlier post).

I use a product called Swarfega Jizer. It degreases and protects against rust. It is also water soluble.

Thank you everyone for all your kind advice.