Lab metal question

[NeoMoses]

I've got some holes I need to fill in a part, and the part will need to be anodized afterwards. My options (as I see them) are these:

1. Tig weld
2. Fill with some sort of epoxy/filler
3. Continue with holes in part (not desired)

What I'm wondering is this: how does the lab metal hold up to the anodizing process? Will the electrolyte harm it? Will it anodize at all, or will it remain inert? What color is the lab metal when it is fully cured (dull grey or shiny silver)?

[FM]

Tig weld the holes with a 5356 filler rod and it will anodise the same color as the parent material.

[NeoMoses]

One of my fears with TIG welding would be the possible warping of the part. This is a machined part, and has tolerences to +/-0.0005"... I'm thinking that welding it may affect these tolerences.

Cosmetically, small uncolored 'dots' from where the lab metal fills the holes would be preferred to having holes...

Whatever the case, a loss of tolerences is not acceptable. (should have said this in previous post). Thanks for any help!

[Tim Wiltse]

Neo,

Over in e Plating forum Caswell said you can't plate over it so I would think anodizing it would be out too!

LAter,
Tim

[non-stick]

saw this and just thought I'd offer some advice. Lab Metal is a polymer based filler. Albeit one that's tougher than all get out, it's mainly reserved for the powder and liquid coatings guys. It is drillable and tap-able and quite permanent in that sense.... but the end result is that it's a metal filled epoxy if you will and should be treated as such. If you can do something over plastic, then you can do it over lab-metal. If only true aluminum or steel will do for your purposes, then metals should be used. Think of it as bondo on sterroids if you will . Hope that helps somebody out there..... warmest regards to all, Russ

[whistule]

Can you not make up another part to fit into the hole? You could glue that in place and then with the right surface treatment the join would disappear.

[Fibergeek]

Since you aren't afraid of close tolerance machining; and aluminum TIG or MIG welding is disallowed, and assuming the holes are round.

Ream the offending holes to a slightly larger and known diameter. Turn an aluminum plug (in a lathe) to a diameter oversize enough to provide a press fit in the reamed hole, consult Machinery's Handbook for the proper allowance. Press in the plug, trim it flush with the surface, and and prep the part for anodizing. The press fit plug will make excellent electrical connection to the work.