DTM (direct to metal ) Epoxy selection

Discussions about general body work and modifications
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Kingspeedy2
Posts: 272
Joined: Tue Mar 31, 2015 2:36 pm

DTM (direct to metal ) Epoxy selection

Post by Kingspeedy2 »

My 65 shell is ready for media blasting (walnut and Aluminum oxide in the few rusty spots) and I want to protect it with a coat of epoxy ASAP
I was going to wipe on some Eastwood afterblast which will leave a zinc phosphate coating on it.
This will protect it from rust bloom,then immediately before painting scuff it with a DA sander and wipe it down as per the Epoxy manufactures Spec

A body shop close to the blaster is doing it as I live a ways away and want to get it coated ASAP after blasting
they use Valspar but will use any product I supply ,I was thinking Sikkens or Dupont

my questions are
1) What brand of epoxy have you used?
2)Any of them specifically mention not compatible with a Phosphate coating (I have read about some that say not to be used but cant find the articles again)
3)do I need to epoxy in areas I was going to use POR 15

I will get Data sheets on whatever products and have emailed a few manufactures about the Phosphate compatability
as most new manufactures have a phosphate dip as part of their MFG process

Lou's Comet
Posts: 1539
Joined: Sat Nov 26, 2011 8:56 pm
Location: Jeannette, Pa.

Re: DTM (direct to metal ) Epoxy selection

Post by Lou's Comet »

Kingspeedy2 wrote:My 65 shell is ready for media blasting (walnut and Aluminum oxide in the few rusty spots) and I want to protect it with a coat of epoxy ASAP
I was going to wipe on some Eastwood afterblast which will leave a zinc phosphate coating on it.
This will protect it from rust bloom,then immediately before painting scuff it with a DA sander and wipe it down as per the Epoxy manufactures Spec

A body shop close to the blaster is doing it as I live a ways away and want to get it coated ASAP after blasting
they use Valspar but will use any product I supply ,I was thinking Sikkens or Dupont

my questions are
1) What brand of epoxy have you used?
2)Any of them specifically mention not compatible with a Phosphate coating (I have read about some that say not to be used but cant find the articles again)
3)do I need to epoxy in areas I was going to use POR 15

I will get Data sheets on whatever products and have emailed a few manufactures about the Phosphate compatability
as most new manufactures have a phosphate dip as part of their MFG process
I use PPG epoxy DP90LF or their Omni brand epoxy MP172. The PPG has a longer window than the Omni to topcoat without sanding. 7 days vs 3 days. Do two wet coats. Have been using PPG epoxy for over 25 years and never had a problem.

After blasting sand with 80-180 grit and clean very well!! Then spray the two coats.

I don't use Phosphate coating with epoxy, really see no Benefit to it. I always sand with 80 grit before I spray the epoxy which removes any and all flash rust. Also I have seen the Phosphate cause problems and fail in the past. Never had the epoxy fail.

POR 15 does not like clean metal!! POR 15 sticks very well to rusty metal but not clean metal. If your going to use it on clean metal you need to use their prep "metal ready" first which etches the metal and kind of flash rusts the metal for the POR to stick and IMO it still doesn't stick as well as epoxy on clean metal. I have had POR fail on clean metal. Works great on rusty metal though.

Here is the sheet on the DP epoxy
http://us.ppgrefinish.com/getmedia/A032 ... r-9-13.pdf

And the cheaper Omni, which is still made by PPG
http://us.ppgrefinish.com/getmedia/74B5 ... s-8-13.pdf

I have used both with great success.

Lou

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