stevenmurray

<center><img src="http://pictureposter.audiworld.com/37382/struttowerhalfround.jpg"></center><p>I was almost going to fill it with caulk, until I saw how symetrical the hole is. I'm going to paint prime where there was some scraping with the upper spring perch. Now it looks like the half-moon is a drain or something intentional.

It looks like the metal is double thickness, as seen from above in the strut hole.

auditqc83

mine has uh...

stevenmurray

I don't plan to top coat it with paint. Is that OK? Is 'DuPont Etching Primer - Grey' better?

beermonster

Mine has it too. I reckon that it's a drain hole..

Katman

Primer isn't typically 'waterproof', as it's expected that a top coat of something else will be applied. (How many 'primered' cars have you seen on the road, with rust starting again through the primer?)

Primer is made more for it's adherance qualities, and not so much for it's protection qualities.

(Besides, if you don't top coat the primer, it looks like you haven't finished the job! You could always spray on some undercoating on top of the primer..)

stevenmurray

I took an autobody class last year and the instructor said lacquer primers of yore would let water through but the new stuff handles weather and water well. At the same time he was mixing it fresh adding hardner and reducers. He did say this Transtar was a good primer considering it comes in a can.