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Epoxy vs Etch primers for bare metal + process


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#21 24TZ

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Posted 17 September 2014 - 09:22 PM

Thanks for that info. I would have thought bog on bare metal would have been fine aswell.

#22 scott

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Posted 17 September 2014 - 11:04 PM

I epoxy then filler then re epoxy then prime. I also dont touch any bare metal without gloves.

#23 gav240z

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Posted 17 September 2014 - 11:38 PM

That is old school way Gav, mine is done like that and most of the bog that was done 20 years ago has fallen off with rust behind it, can show photos if needed,  supposedly the heat reaction causes the bare steel to sweat, that is why new school do it on top or  etch primer.


In fairness I didn't see a teacher doing it this way, it was another student in the paint section doing it.

I epoxy then filler then re epoxy then prime. I also dont touch any bare metal without gloves.


Yes I tried to avoid any bare hands touching the metal after blasting.

#24 neRok

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Posted 18 September 2014 - 09:45 AM

AFAIK, bog is porous, which can explain the rust under it (especially if it was wet sanded).

#25 reverendzed

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Posted 18 September 2014 - 11:34 AM

OK - Unless there is some very new, tried and tested products- I've never seen success with putting body filler over anything except bare metal.  If you check out what resto and custom shops are doing (youTube) you will see that it is all bare metal body filler work.  The bare metal must be prepped correctly and you NEVER wet sand body filler anyway.  You only need to get it to where your Primer/surfacer - preferably 2 pac epoxy (dry sand) will fill your scratches and not shrink back after top coat.  There is a plethora of info, how to's and DIY on youtube - check it out.
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#26 scott

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Posted 18 September 2014 - 10:01 PM

PPG advise epoxy then filler then re epoxy.

#27 Brabham

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Posted 21 September 2014 - 09:52 AM

My TAFE teacher also said to do it over bare metal, however unless the metal is perfectly clean and the Nikki/hardener ratio perfect, I have been advised it is likely to rust underneath. I am doing epoxy/etch then sanding it to get a good key for the filler as some others are doing it. It seems the jury is still out somewhat, however I prefer this method.

#28 nat0_240_chevZ

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Posted 24 September 2014 - 10:56 PM

old hat methods vs new hat best practice.
always hard to convert the foagies, most never re-train anyhow, and that includes 'trainers' themselves.

If we lived by the old philosophies, F1 would still be steel caged cars, our forum would consist of pen & paper and maybe we would never have discovered light & lasers.
boy has the world come a long way in the last 60 odd years....too bad the motor car has not!

I would only recommend treatment of raw steel, either phosphate or chromate resultant products.
Of which the super etch is one of a handfull of the best there is as far as a 1k ep etch suitable for almost any further surfacing/finishing.
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#29 EVIL_denver

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Posted 25 September 2014 - 12:43 PM

there is no right or wrong, no way is better than the other. The BEST way is always by the manufacture specs. Personally ive used etch primer and epoxy, filler over metal and filler over epoxy. I found that is much much easier to just epoxy the entire car and take your time with the filler work. You will need to give the epoxy a scuff so the filler bites. If you are putting filler over bare metal, you need to work fast because it is porous and moisture will get under it. If a lot of moisture gets under the filler it will blister the paint down the track when the oxygen in the moisture want to escape... this is not good and would require a full bare metal respray again. 

#30 zeds4ever

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Posted 29 September 2014 - 11:25 AM


  Tried to buy Wattyl super etch primer at Bunnings some time back, was told that they don't sell it anymore. Also local paint shop
informed me that "White knight " is a Wattyl product .

                                                          Regards: Alan.




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