Thoughts on bead blasting lugs

[Dorman]

I was discussing metal prep with my friend today (whose shop I will be using) as I was showing him the lugs and tubes we will eventually be working with. He suggested bead blasting the lugs as a final clean up step prior to brazing. Just wondering if anyone is doing this and if there are any reasons it would be a bad idea?

[Eric Estlund]

I haven't tried bead blasting, but I have had to braze through sand blasted areas. Two much tooth and it's more challenging to get good flow and wet out. I don't know if the same would be true with bead blasting, but so far I've had best success flowing over a bright finish.

[Dorman]

Thanks Eric, that is good info. Bead blasting will certainly leave much less tooth than sand blasting, but I'm not sure I'm willing to experiment to find out if it will work or not.

[zank]

I would also worry about blasting contaminants into the steel if it's a multi-use blasting cabinet.

[e-RICHIE]

just get some 80 grit aluminum oxide cloth and show the parts who's boss atmo.

[Dorman]

just get some 80 grit aluminum oxide cloth and show the parts who's boss atmo.

That's what I was telling him when the question came up. Sticking with original plan. Hey Mike, another good point I hadn't thought of.

[Mark Kelly]

Metal finishers are conditioned to work in Ra values so all you really need to do is specifiy the value you want and the shop will do the rest. Broken beads in recycled bead blast generally raise the Ra value so if you specify a lowish value contamination shouldn't be a problem. If needed simply specify that they are to use new media for your work.

Ra is "Roughness Average" and is basically the average height of the surface features, so smaller is smoother. As a guide, Ritchie's P80 grit cloth will give a surface finish around Ra = 2 μm. Bead blasting can achieve a finish from Ra = 6 μm down to Ra = 1 μm.

[EricKeller]

my experience is that blasting lugs works fine. I usually only do it with things like stainless dropout sockets that are annoyingly small.

[Brian Smith]

Serotta did a good amount of blasting lugs in the past.
It doesn't "NOT WORK."