What is a good material for masking holes?

[rayginn_mfg]

I have some small tapped hole and some very fine threaded holes, what should I use to mask them. I will be anodizing Black.

[rclint]

I have some small tapped hole and some very fine threaded holes, what should I use to mask them. I will be anodizing Black.

Are you masking to keep them from anodizing for some other reason than changing the dimensions ? If all you are worried about is everything fitting together after anodizing I would make a trial run and see what happens, I have anodized parts with threaded holes and no problems fitting after anodizing.

You should be able to find some type of malleable "spongy" material to just roll up and let it conform to the inside. How small are you talking ? You might also try a hot glue gun.. easiest way by far is no masking.

Clint

[sswee]

Caswell sells silicone plug kits for powder coating that work well.

[kickn]

I use silicon plugs mostly now.

I have in the past pulled bits of silicon tubing through the hole and have (and still use) some pcb pealable mask. Look for one that is acrylic based and you should be fine. The only problem I have with it is that it doesn't hold up to the degreaser I'm using so I have to degrease - wash - dry - mask - dry - then etch

[acidrain]

I'm much cheaper than you guys. I use rubber stoppers for anything 5/16in and over, and small bits of hardwood dowel sharpened in a pencil sharpener for smaller holes.

[rayginn_mfg]

Thanks for the info. I made some nice nylon threaded plug on my cnc lathe. Thanks again.

[sswee]

Nylon is not the best choice. It won't hold up to the acid.

[cameraman]

Nylon is not the best choice. It won't hold up to the acid.

I've done two runs with nylon 'hardware' bolting the wire to the piece, and thought I was pretty clever. Is it going to soften and fall apart after another run or two? I thought I'd found the Ace alternative to titanium...

[sswee]

I am going from previous post from guys that had tried nylon and a CRC (chemical resistance chart). You can get a CRC from Little Giant Pump site in PDF format. It doesn't list all materials but enough of the main ones.
SS