Garden Railway Forum

Need to fill in small drill holes in steel at the moment but maybe brass later.

Can I use car body filler such as below?

http://www.c1.halfords.com/motoring/pai ... sand-250ml

Cheers,

Tom

Body filler works. Solder does too and is better long term for small holes.

I've used one of the epoxy filler/adhesives like Chemical Metal or JDweld. I'm not a fan of Araldite but have used this as well. If the material is not paper thin then ideally countersink the holes even if only by shamfering the holes with a file or use a large drill so the adhesive/filler creates a rivet. Make sure you put plenty on then file down to a finish once cured.

tom_tom_go:103967 wrote:Need to fill in small drill holes in steel at the moment but maybe brass later.

Can I use car body filler such as below?

There's no single method, it depends on the material thickness and the hole size.

For small holes in thicker materials, say 1mm and up, I usually fill it by countersinking each side and rivetting a piece of wire or rod of the relevant metal into the hole then dress it smooth. Do it right and you'll never see the repair. This is the best way of moving holes that have been drilled in the wrong place.

I also use epoxy putty such as Milliput for this sort of repair if it is just cosmetic and you don't need to drill a new hole very close to the one you just filled.

For small holes in thin metal, such as brass body work, you can usually fill the hole with solder. Use plumbers solder which is 70/30 if you can find it as it is less runny and better at filling holes. It can also fill deep scratches and gaps in joints by wiping, which can be useful.

For large holes in thin metal, the only way to get a strong job is to solder a thin backing piece on the inside and filling the resulting recess. The strongest repair will be to cut a piece of the same metal to a reasonable fit in the recess and soldering it in place with a lower melting point solder, known as step soldering. Otherwise fill with epoxy putty which sets hard and sticks well.

Epoxy putty isn't as heat resistant as solder, which needs to be kept in mind on steamers. Body filler used in car repairs is pretty much useless in this application, although still useful for filling minor dings and scratches as part of preparing the surface for painting.

If you have to fill a hole in a smokebox wrapper, the best method would be to fill the hole by rivetting a piece of wire or a rivet into the hole. Tapping the hole and then fitting a screw with the head on the inside, hammering the protruding thread down into a countersink and finishing flush also works well. If you are good at silver brazing, it will also fill small holes in thicker metal.

Regards,
Graeme

Thanks guys.

As always Graeme we hail your words of great wisdom