removing Polypropylene from cast iron fire

[rob w]

Hi all Hope some one can help; my son's friend after playing in the snow put his gloves on top of our gas fired cast iron stove to dry out. I was alerted to this by the smell of the melting gloves. My immediate thoughts were to get as much of the pool of plastic off the fire ASAP. the problem now is it has left a thin smear of plastic (polypropylene) on the cast iron and try as I can I cant get it off. Any ideas or anyone know of a solvent. I'm guessing its polypropylene as I checked a pair of similar gloves.

Cheers Rob

[doozer]

Acetone will probably shift with a bit of rubbing it but *make sure the fire is off and cold* or you will burn the house down and likely kill yourself into the bargain.

Failing that you could try and get hold of dichloromethane (aka Methylene Chloride) that shifts just about all plastics. Not sure where you would get it neat though (a chemist friend could get you some or check out paint strippers). Don't get it on yourself though as it can cause permanent hyper-sensitivity to it and has been flagged as carcinogenic (but it doesn't burn so there are some upsides).

Finally you might like to try methanol (pink meths). I don't hold out much hope but it might work.

Graham

rob w wrote:

[Grunff]

Acetone will not dissolve polypropylene to any measurable extent under normal conditions.

Neither will ethanol (which is what meths is made of - not methanol).

Chlorinated solvents will to some extent (as you suggested), but PP is really very difficult to dissolve. Hexane will soften it, which may help in removing it.

[doozer]

Oh yes silly me. It's denatured with methanol not made of it.

I have just a look in a couple of old text books. Apparently hot toluene or other non-polar solvents will work with extend exposure (IIRC petrol is fairly not polar) I don't think you will be able to get hold of toluene or hexane (both quite nasty).

If you can get the fire apart you might try burning it off but I suspect that would leave the metal tarnished. You would need around 300 deg C with a good flow of air (more air the better).

Graham

[Mary Fisher]

Some years ago I did the same by resting my feet on top of a gas fire. I then made the mistake of standing on the wool carpet.

The soft stuff scraped off the fire easily but, as you say, left a residual smear which we still live with. No solvents we could get hold of (we both had links with industrial chemists) would touch it.

That which was left on the carpet looked like a patch of cat doo. The carpet has now been discarded, not because of that but you brought the memory back :-(

Mary

[John Rumm]

How about melting another pair of gloves and wiping the goo in a thin film over the whole fire so that it matches? ;-)

[Mary Fisher]

That's my style!

Mary

[Sue]

Forget it - you will not get polypropylene off with solvents, for mundane purposes it's inert.

Why not just light the fire, scrape off as much as you can when it starts to melt, and let the rest burn off? It's not hard to ignite once it's warm.

To cover the mark, you could do what great-grandma did and blacklead the stove. I wouldn't bother until the cold weather's over, but YMMV.