Porsche 928s Restoration Prep

T

Theinbaugh

I recently purchased my first SPI products. I have my suspension parts stripped and am just waiting for an opportunity to spray the in black epoxy. I have some experience spraying but have never applied epoxy and am excited to give it a try.
The suspension parts are a pretty straightforward strip, clean, and spray but I have been researching body prep. I am sanding the body panels when waiting on other items and finishing other "To Do" items. When sanding I have been careful to take off only PO color change (crappy) paint job and the original bc/cc down to original primer/base. In reading as many relevant post I have a question about epoxy adhesion.
It is recommended on the P car forms to leave the original underlying epoxy/primer as all panels except trunk deck are aluminum. The body shell, steel parts, are galvanized so it is recommended not to break thru when possible. If the OEM base, or as much as possible, is left intact is there any issue with adhesion of the SPI epoxy?
Plan is to go back with 55 line original 661 base and if compatible, SPI Euro clear. Pictures are, white
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as bought, blue is color correct. Thanks in advance and this forum is full of awsome advice. Tim
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SPI epoxy has no problems sticking to aluminum or galvanized, as long as it is cleaned with 700 and has a sufficient scratch. The factory epoxy primer needs a 180# scratch as prep for SPI epoxy, metal needs 80#. Those suspension parts look nice and clean, but look almost polished. A wire brush or surface conditioning disc surface doesn't have enough tooth for best adhesion.
 
DA with 80 grit gold paper. Hand scratched with 80 were the DA won't fit. Which reminds me, the cast parts, torsion bar and calipers, any special treatment besides scuffing with 80?
 
DA with 80 grit gold paper. Hand scratched with 80 were the DA won't fit. Which reminds me, the cast parts, torsion bar and calipers, any special treatment besides scuffing with 80?
I'd have to blast those parts, would be very quick at this point.
 
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