Question re using scotch brite pads to deburr.

In those cases where there's not enough room to use a deburring tool and you use a scotch brite pad, does that always remove the aluminum cladding such that you must use primer? I've never been able to leave holes smooth to the touch without also leaving a dull finish. Does 3 to 5 passes with a scotch brite brite pad strip away the protective layer of aluminum?

Yes. If you remove the Alclas, then it is wise to use something else to prevent corrosion, like primer. Not to start another primer war, but if you don't plan to use it, then don't debur with a scotchbrite pad.

bobhope2505 said:

In those cases where there's not enough room to use a deburring tool and you use a scotch brite pad, does that always remove the aluminum cladding such that you must use primer? I've never been able to leave holes smooth to the touch without also leaving a dull finish. Does 3 to 5 passes with a scotch brite brite pad strip away the protective layer of aluminum?

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Three to five passes with a scotchbrite pad should dull the finish, but I can't see that it'd strip the alclad away. This is a hand-held pad, and not something on a palm sander or die grinder right?

Incidentally, I never found a place on my RV-6A that needed to be de-burred using a scotch bright pad. For those areas where I couldn't get to with the standard deburring tool, a 1/4" drill bit twisted by my thumb and forefinger with just a little pressure worked awesome.

Using a scotchbrite pad is fine and it would take a lot of effort to go through the clad with a handheld pad. I always use an alodine pen to touch up bare aluminum at a minimum prior to assy.

Thanks. Not using a sander. The issue came up working on the elevator tips. The taper toward the back gets too narrow for any kind of tool.

Kudos to the Van's team on one part (can't recall which right now) where they punched it prior to bending from would become the inside surface. All the burrs were facing outward. Nice!

I always scotch brite my parts. Except stainless parts of course. It doesn't matter the way that you prime the parts, the more surface area that is available for the primer to stick, the better. Plus any kind of burrs or sharp edges will be susceptible to stress risers. Deburring with a scotch brite pad fixes that. Just a quick peace of mind test, micrometer the piece before and after scuffing. The alclad is 2024 on the inner part with normally a 1230 or 1100 surface. Which is about 99.3% to 100% pure aluminum. I also believe this alclad surface is about 5.5% of the sheet. You can figure the dimensions out yourself. Bottom line is, reasonable scuffing is good.

At least in my opinion!

I miked some yesterday. 4-5 swipes with red Scotchbrite on one side made no measurable difference. Using a pad in a die grinder to really hit one side good reduced it by about .0005.

I've made tools to deburr places that are hard to reach. I would not trust scotchbrite pads used by hand to adequately deburr and remove potential stress risers. Just my opinion.

wilddog said:

I miked some yesterday. 4-5 swipes with red Scotchbrite on one side made no measurable difference. Using a pad in a die grinder to really hit one side good reduced it by about 0.0005.

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And the Alclad thickness is nominally 5% per side - 0.00125 for 0.025 material.