Paint question....whats the best method for painting of e-coated fenders..

[bandit67]

Got roped into squirting some color on a fender and lower valance panel.  Have no intentions of repainting the whole truck for the kid to crack up again, but , what are the steps to use to get the panel ready for topcoatiing. Does the e-coating need to be sanded? coated with a primer/sufercer? final sand and topcoat?   Have very little faith  that the kid won't wreck it again.......so perfection is not the goal.  thanks , guys , for your input.........J

[Doc74]

Does the e-coating need to be sanded? coated with a primer/sufercer? final sand and topcoat?

Yep and if the e-coat has scratches don't hesitate to sand them out to bare metal, don't try to fill them with the primer.

[Charger-Bodie]

e coat doesnt need to be sanded if you use the right sealer im not familiar with other paint lines but with sikkens color build sealer you just sand out box marks or scratches , wipe it down seal it , then paint it.....the chenical adheshion of the right sealer over e-coat is actually better than the mechanical adhesion of sanding it plus e- coat is one of the best corrosion resistant coatings there is!!

[69 OUR/TEA]

1hot68 is absolutely correct,e-coat is the best substrate to be on bare metal,hands down!!!DO NOT STRIP IT,sand out the scuffs and /or scratches.I use PPG,their DP epoxy is designed to go right on top of properly cleaned,unsanded e-coat!!!! One or two coats and then use your topcoat as desired.

[Silver R/T]

leave it on there, just scuff it before you primer/seal it

[Doright]

What is Ecoat?
I know what your talking about, I have seen it on new panels for newer cars. I have even installed the panels on a few cars I just scuffed and painted them but I was curious as to what kind of paint it is.


Electrostaticly Painted?

[Charger-Bodie]

leave it on there, just scuff it before you primer/seal it

ya dont eve scuff it if you use the right sealer

[daytonalo]

Yea like the extra insurance of adhesion by scuffing might kill you !!!!!!!!!!!

[Charger-Bodie]

Yea like the extra insurance of adhesion by scuffing might kill you !!!!!!!!!!!

actually wise ass the scuffing hurts the chemical adh. so if you are gonna scuff it you may as well sand it cause youre back to mechanical adheshion

[Doc74]

I don't know what types of e-coats you guys are used to but the ones I've been working with HAVE to be sanded.  They are non sanding primers but that doesn't mean they don't need sanding.  To be clear, when I say sanding I mean getting the shine and structure out, not sanding to bare metal everywhere.

The e-coat is a catalyzed transporting primer, it can be coated with other paints within a certain time frame (hours, not days or weeks), as they do in car factories.  The e-coat on replacement parts is a base to protect the piece.  Some are rock hard while others feel soft and can actually take advantage from being removed alltogether.  I would, at the very least,  scuff the panel and apply an etch primer.

I'm sure they guys here using the sealer know what they're doing, it's just not something I intend to use.

[Charger-Bodie]

its just hard for some to accept new technology , and i admit it took me awile to take advantage of it myself but after lots of testing and being thouroully trained on the method i will never go back....................so if you want to sand off the best available corrosion resistance, go ahead and do so but ill just to it the way the paint manufacturer suggests to. onne last thing if there was anything wrong with this method , do you think a paint co who warrentees the products and the performance whoud tell you to do it if they felt they were gonna have to paay you to redo it? duh i think not!!!!

[69 OUR/TEA]

PPG DPLF....

[Doc74]

its just hard for some to accept new technology , and i admit it took me awile to take advantage of it myself but after lots of testing and being thouroully trained on the method i will never go back....................so if you want to sand off the best available corrosion resistance, go ahead and do so but ill just to it the way the paint manufacturer suggests to. onne last thing if there was anything wrong with this method , do you think a paint co who warrentees the products and the performance whoud tell you to do it if they felt they were gonna have to paay you to redo it? duh i think not!!!!

I'm sure it'll hold up but I don't see anything wrong with sanding.  Afterall the black is not the actual ecoat, the clear zinc phosphate underneath is, which you don't sand.  You can see the difference when you do sand through it.  But that's not the point now, I understand why you use a sealer and of course the paintco wouldn't back it if it didn't work.  Altough others likeTranstar say : Optional: Parts can be scuffed with a scuff pad prior to priming for improved adhesion.  About the same thing my Sikkens supplier told me.

So what do you do when you have scratches or other damage on the ecoated panel?  How do you prep those?

I'm not trying to be right here, I just believe sanding, or scuffing is the better method.  It's how I learned it and it's how my paint suppliers recommend it.  If applying a sealer is better then that's the way I will go, I just would like to have a little more info before I do so, so if you have some tech sheets in your bookmarks or something I'd be happy to get a link to those.

[Charger-Bodie]

doc with damaged parts or a box rub or whatever a small amount of sanding is needed what i was saying about not scuffing it because its worse is true scuffed = worse adhesion because it changes the properties of the sealer so the chemical adhesion is lost . so its ether sand it very good or dont sand it at all and yes i use sikkens too but a couple hundres miles from home right now so ill try to post a page tommarow

[Doc74]

doc with damaged parts or a box rub or whatever a small amount of sanding is needed what i was saying about not scuffing it because its worse is true scuffed = worse adhesion because it changes the properties of the sealer so the chemical adhesion is lost . so its ether sand it very good or dont sand it at all and yes i use sikkens too but a couple hundres miles from home right now so ill try to post a page tommarow

Thanks a bunch, I appreciate that and no rush, I'll be in and out the house as well the next few days.
Have a good one.

[Charger-Bodie]

doc with damaged parts or a box rub or whatever a small amount of sanding is needed what i was saying about not scuffing it because its worse is true scuffed = worse adhesion because it changes the properties of the sealer so the chemical adhesion is lost . so its ether sand it very good or dont sand it at all and yes i use sikkens too but a couple hundres miles from home right now so ill try to post a page tommarow

Thanks a bunch, I appreciate that and no rush, I'll be in and out the house as well the next few days.
Have a good one.

here is where it says colorbuild can be sprayed over ecoat:

[hemi-hampton]

I noticed the PPG said only if the 401 used, How do you know if the 401 was used unless you actually sprayed it yourself? Plus, I hate the 401 & always use the 402 instead. With the 401 you have that what they call 1/2 hour Permeation Period. Anywhere I work it's rush rush rush, Who has a 1/2 hour to watch & waite for Primer to permeat? Whatever the hell that means? No waiting with the 402 catalyst/hardener. LEON.

[Charger-Bodie]

I noticed the PPG said only if the 401 used, How do you know if the 401 was used unless you actually sprayed it yourself? Plus, I hate the 401 & always use the 402 instead. With the 401 you have that what they call 1/2 hour Permeation Period. Anywhere I work it's rush rush rush, Who has a 1/2 hour to watch & waite for Primer to permeat? Whatever the hell that means? No waiting with the 402 catalyst/hardener. LEON.
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so you would rather sand for an hour and remove alot of a parts corrosion resistance than go into the mixing room 1/2 hr before sealing apart and have the ecoat intact?

[hemi-hampton]

I've heard of this Technique awhile ago & again recently while attending the PPG Paint school here in Detroit Area (wixom). My problem is getting use to this new method & getting the right sealer & sometimes in a body shop you have no control over buying/getting the right Material as most body shop owners are only concerned with whats cheapest. My preferred method is to lightly sand with 320 or 400 grit. Only material that may get removed is slightly on a edge. Sanded edge not much of a concern as I always seal my parts before I paint, usually with a PPG DP Primer, DP40, DP50, DP74, DP90 ect.  I like the many different color options of the Sikkens colorbuild. Once when doing a FC7 Plum Crazy Purple car I mixed both Blue & Red colorbuild together to get my own purple sealer. Worked great & covered quick. LEON.