cellulose over hammerite spray paint.

Why not try it and see, on a piece of scrap?

I'm pretty certain that the Hammerite will be wrinkled by the cellulose. However, you could spray the Hammerite with a barrier spray first to avoid this.

Rob Graham

Hammerite is overrated as a rust preventer. There really is only one way to do it properly, remove all the rust, prime it with a good quality primer, and topcoat accordingly. If removing all the rust means cutting out all the bad metal and welding in new, then that's how to do it. Any less is a bodge.

However in the real world, the rust is sometimes inaccessible. In that case you might resort to a rust converter before priming and painting. But having tried it on chassis in the past, Hammerite straight over rust will rust again later.

Chris Bolus ( snipped-for-privacy@FARINAb0lus.com) gurgled happily, sounding much like they were saying :

It's 'orrible stuff. You've got to be immensely careful in the prep, else it flakes and chips easily, it's very susceptible to fuel or oil, and it's a bastard to get off brushes.

Yup. I used Smoothrite to paint a wrought iron garden gate after treating the rust with jenolite. Did the same to the railings then painted that with Dulux. Both black. After about 4 years, they need doing again. Fairy nuff - except that Smoothrite is many times the price.

Cellulose 'cooking thinners' can clean brushes. Even dried ones, and it's cheaper than Hammerite thinners. Only a few quid for 5 litres. Even cheaper still, if the brush is still wet, is to use parrafin with a wire brush. I use Hammerite quite frequently to paint welded fabrications at work, and have been using the same brushes for years. Mostly cleaned using parrafin. Mike.

Blacksmiths acid etching black primer, you don't want it on your car but it's great for wrought iron.

Thanks - I'll try that next time. Where would I get it?

I've never had trouble cleaning brushes - you've got to use cellulose thinners.

Hammerite smooth is not overrated - many people simply don't follow the instructions and paint it on too thinly. But, I grant that many non-Hammerite gloss enamels will work just as well applied in similar film thicknesses. It's not a particularly flexible paint when cured but not many "enamels" are.

Cellulose on Hammerite? The Hammerite must be left for _weeks_ to fully cure. It is then _just_ possible to spray over cellulose and avoid wrinkling but only if you spray very light coats with a good deal of drying time in between (less solvent left on the surface).

IMO Hammerite smooth is particularly good for remedial work to underside "non-cosmetic" areas of the car, but just wirebrushing the rust off is not sufficient - my regime is this...

Grind the rust off gingerly with anglegrinder or drill attachment Apply Jenolite in several passes, using screwdriver / wirewool to work it in Apply Hammerite smooth in one megathick brushload to the point of dripping (You can apply in several coats but timing is crucial and if it's not seen then why bother?) Apply Tetroseal body sealer over the smoothrite. Daub the bloody stuff on.

You can substitute pretty much any good thick enamel for smoothrite. The key is keeping air and moisture out of the afflicted area. I guess that only 10% of benefits are added by in-mixture antirust compounds.

Rust can be stabilised during the working life of the car, but beyond a certain point unless you're loading the area with duck oil, and repainting every 3 months some rust will be unstoppable.

Best of luck, Ken. DocDelete

I buy it from my local blacksmith :-) I think it's made by stokes, IIRC Trimite do one as well.