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Old 10-24-2017, 02:48 PM
crystallographic crystallographic is offline
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Location: Western Sierra Nevadas, Badger Hill, CA
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Quote:
Originally Posted by lots2learn View Post
I want to know if it would be OK to use my blast cabinet to clean the little pits of rust left over after stripping disc. It uses white Aluminum Oxide and is a pressure pot type cabinet. Will run reliably down to 20psi. If I keep the angle shallow can I avoid stretching and damaging the door panel? Or should I use some other method like chemical to get ready for epoxy?


Please disregard the bottom of door. That will be replaced.

Attachment 43723 primer?
I would blast that - with light fine media that is sharp. Keep moving. Go back at the end and go over again, keep moving.

Blow clean and use an acid etch - that lowers the oxidation potential of the already-rusted steel.

Long-time "Rusties" (rust-repair fellas) notice that rusted areas that have been blasted/soaked/abraded always re-rusted much more quickly in those same areas.
- unless those areas were either treated with a phosphoric acid neutralizer, or heated to 1200F.
One excellent product here:
http://www.tinmantech.com/html/must_...ver_inhibi.php

If your acid-etching primer has phosphoric in it then you are all set.

This formula for the above product was developed during WW2 as an industrial product (MP-7) and sold only in 55gal drums. It is now a "consumer" product that still may be ordered in bulk.
I have used this for 25+ years with zero problems, and on some pretty valuable clunkers. (one of the photo pairs is of a P40 drop tank that I split, saved and welded back together.)

Follow directions - grease/oil free, wipe up excess, use in warm ventilated area ....
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"All it takes is a little practical experience to blow the he!! out of a perfectly good theory." --- Lloyd Rosenquist, charter member AWS, 1919.
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