I am going to take my chevelle down to bare steel for new paint. After minor body patch in quarters I was going to apply PPG etch primer, then epoxy, then filler, primer surfacer and finally base and clear. The question I have is after the car is in epoxy, the filler applicaton will extend past the epoxy window. Would I recoat once with epoxy after the filler is finished. This leads me to believe that I should put filler directly to metal, then etch around the filler then once over with epoxy.?? Also is blocking through the epoxy to steel allowed as long as it is covered with primer surfacer before paint?

Rule of thumb is that plastic fillers should go on properly clean rough bare metal for proper adhesion.
Once your done with the dent work you then follow up with two dustings of etch on only the surounding bare metal followed by "4" coats of high build primer. This will alow you to block out the primer for a smooth finish. Just an added note you can use a polyester filler(Evercoat)over your primer with good adhesion to fill scratches dings etc.After you now have the suface as perfect as you want,(primer blocked out). As an option you can then apply sealer just before you paint color. The sealer will provide you with better topcoat holout(Dye back)
Another note is to never apply fillers on etch primers. The plastic will never dry due to the reaction, only primers can be applied over etch.
Some of the paint manufactuers are saying you can apply plastic fillers over there primer,I am not real comfortable with this idea just yet.
On the subject of epoxy primers we only use epoxy on new parts that do not need body work.
It is not considered sandable.We use it also on bare frames etc.before we topcoat,again no bodywork.
In the past it was used in place of sealer due to it's great sealing and topcoat holdout ability.
Sorry to ramble and i hope this makes sence. There is so much more that could be said on these products but this hofully will get you started.

When you say dusting of the etch, I assume that you mean it just wets the surface and does not cover? Also how do you keep the etch off of the filler, is this why you dust the coat? Also, if after the urethane surfacer blocking I find low spots is it true that you have to use polyester fill only?

Rule of thumb is that plastic fillers should go on properly clean rough bare metal for proper adhesion. Actually you can do filler work over epoxy and some auto manufacturers recomend it for repairs. This makes for a slow process, allowing the epoxy to cure before doing the filler work, but it makes for a very durable repair. Apply some more epoxy over the filler before moving on to the primer surfacer. The epoxy over the filler will provide an excellent solvent and moisture barrier. Not everyone is a big fan of epoxy, mostly because of it's slow cure rate, but it's never failed me yet.

You don't "dust" the etch primer on. There are no tech sheets I have ever seen that say "dust" a product on.

PPG's DX1971 has a recommendation for one "light coat". I understand that "dust" and "light" may be the same to someone but they are not. "Dusting" is a much drier application. PPG's DPX170/171 have a recommendation of "two wet coats".

You need to apply the proper amount of etch primer or it is not going what it designed to do.

This is a great site for PPG tech sheets Tri City tech sheets (click here) (http://www.tricitypaint.com/docs.html)

Thank you for the information. I will strip to metal, do filler work, mask the filler, spray etch per tech sheets, prime with k-38, block, seal, paint and clear.

Religiously going by the tech sheets cannot be over emphasized until you become familiar with the products you routinely use.

One of the pitfalls of asking questions on forums such as this is that some people will give what appears to be general advice but it only applies to certain specific brands of paint, but not others. Not saying it's bad advice, it just may be totally wrong if you aren't using the brand of paint that the person giving the advice has experience with. If they've never used but one brand, they don't realize that they are giving wrong/bad advice.

Vette, you are right, in fact there may be a tech sheet that says "dust" a couple of coats on. I don't really mean so sound like that is "wrong". I just have never seen it, but there are tech sheets I have never seen so I shouldn't say "never".

The most important thing to remember is, follow the tech sheets of whatever you are using. There are some very different recommendations out there. For instance, S-W has an etch with only a four hour window before it MUST be top coated. You are not to sand it, it MUST be recoated with it's self if you go over the four hours. That is the only etch I have ever seen with this recommendation. So it is very important to follow those tech sheet recommendations.

WOW isn't it funny how people come out of the woodwork to bash somebody.Yet nobody is giving this guy any definative help. I thought these forums were to try and help another guy out. Lets get down to brass tacks(figure of spech for you guys who take words literally) and give this poor guy some facts if i'm so wrong.

Hold on there buckaroo. People who don't know DO take things literally. You want FACTS read the tech sheets.

Did you read my last post where I explain myself?

You had said most anything I would have, I just wanted to clairify the "dusting" comment.

Sorry you are having a bad day Blue.

Brian, you and I are on the same page. Some brands say their etch can be sprayed over filler, paint and bare metal. Others specify bare metal only. Some brands say their 2K urethane primers can be used over bare metals. Others specifically say they shouldn't be.

I use mostly DuPont paint. If I were to come on here and say "always spray the filler and surrounding bare metal with etch or never use 2K urethane on bare metal", I would be right...but only if I specified that I was talking about DuPont products.

Blue69, sorry, but I've never heard of a paint manufacturer who reommends "dusting" either. Not saying there isn't one, I've just never heard of it.

I'm not a proponent of using epoxy primer at all regardless of brand of paint, so I chose not to get into protracted explanation of my(and DuPont's) recommended procedure for production situations. Yes, DuPont has an epoxy primer, but they don't push the use of it in production situations primarily because of the curing time. Furthermore, I'm definately not a proponent of applying filler over epoxy or any other type of primer. I do it over bare metal only.

The above differences are all the more reason for a newbie to religiously follow the spec sheets of the product they wish to use.

If you are using DX1791 from PPG you do as Martin said 1 light coat. This stuff is darn near clear when sprayed so you wont be able to see it. And if you do you applied too thick!!

It has NO COVERAGE what so ever, when its applied over metal it will have kinda haze look to like.

Also there is NO need to mask the filler off when using DX1791 over filler. The tech sheets say Dx1791 applied over cured painted surfaces and filler are acceptable. Just dont hose it on over filler.

Also depending on the PPG primer surfacer used the number coats varies. If you go with K36(I wouldnt) it can up to 4 coats. But with a higher build like K38 they suggest 2 coats.

Also a good idea when using DX1791 is to wait atleast 30 mins before topcoating with anything. Althou the sheet says 10-15 mins, its cutting it close as the DX1791 is still flashing off. If you topcoat too soon you can loose adhesion between the Dx1791 and the product you applied over it. So wait a good 30 mins even more if you have poor air flow.