Issues with epoxy bond under filler

crashtech said:
Actually, many e-coats ARE epoxies, here is but one example:

http://www.ppgecoat.com/getmedia/b476149d-dd14-4df4-ac35-5e280872d9af/P590-534.pdf.aspx

In virtually all cases, and without regard to coating chemistry, the OEMs tell us NOT to remove their e-coat, and we do our best to comply while completely scuffing the part. It's the knock-off or reproduction parts mainly from overseas that everyone has to watch out for, or really, really old NOS (new old stock) parts.
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WOW, cool I didn't know that. I know where I use to work years ago on the paint line of a manufacturing Co. (for the Lordstown, Oh GM truck plant), they said it was something other (can't remember the name) never said it was Epoxy which was on the E-coat line in another area of the shop. Which consisted mainly of aftermarket replacement parts and Volvo truck crossmembers and small parts for various other manufacturers. That might explaine why they never said it was an Epoxy.
 
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crashtech said:
Actually, many e-coats ARE epoxies, here is but one example:

http://www.ppgecoat.com/getmedia/b476149d-dd14-4df4-ac35-5e280872d9af/P590-534.pdf.aspx

In virtually all cases, and without regard to coating chemistry, the OEMs tell us NOT to remove their e-coat, and we do our best to comply while completely scuffing the part. It's the knock-off or reproduction parts mainly from overseas that everyone has to watch out for, or really, really old NOS (new old stock) parts.
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Note the zinc phosphate! and reason they don't want you to remove, is because they are prepped under perfect conditions that shops and people at home don't have.
Very close example how this is done but does vary .
Auto dipped in first tank, usually 50-55% Phosphoric acid with water..
Dipped in next tank, some will be pure water and some will be a let-down of say 10% acid and 90 water or like and then go to a pure water tank.
Then part is auto dried and dipped in epoxy tank and amount of amps to part dictates the exact mil left on part when pulled out.
Than baked at temp to cure product usually 220 to 400 area depending how everything is set up.

Problem comes in with repo parts, only God knows what some of these hacks use and that is why we test with lacquer thinner or urethane reducer first.
 
Barry, If you had some parts that were acid treated, could you sandblast the parts to remove any residue, or do you have to re-wet with acid and rinse?
 
DATEC said:
WOW, cool I didn't know that. I know where I use to work years ago on the paint line of a manufacturing Co. (for the Lordstown, Oh GM truck plant), they said it was something other (can't remember the name) never said it was Epoxy which was on the E-coat line in another area of the shop. Which consisted mainly of aftermarket replacement parts and Volvo truck crossmembers and small parts for various other manufacturers. That might explaine why they never said it was an Epoxy.
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Well, to be fair, not all e-coats are epoxy, some are acrylic. But if the part is fairly new and comes from an OEM, it's really best not to remove it no matter what it is. The main reasons for this is because the OEM has usually done a great job of treating the metal surface to receive their coating, and also because many parts these days come with galvanneal or similar coating on the metal that really shouldn't be disturbed if at all possible.
 
hudson hornet ! said:
Barry, If you had some parts that were acid treated, could you sandblast the parts to remove any residue, or do you have to re-wet with acid and rinse?
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When i use the acid its on misc type parts, so plan on a Saturday and have a 5 gallon pail from Home Depot with x amount of Ospho I set part in and when clean another of pure water to rinse and another with epoxy to dip and hang up usually with fish line.
If not doing this way i would rewet and clean.
 
The iron phosphate I use for steel industrial parts only operates between 2 and 6% concentration and 140 degrees. Heat always makes them work better. Three stage washers are iron phosphate, rinse, and usually a non chrome seal. 5 stage washers start with an alkaline cleaner, rinse, phosphate, rinse, seal. There are those wonderful things called Molybdates in the seals, it gives the coating an iridescent color that seals the coating from powdering, what is referred to here as neutralization. Molybdates are those wonder ingredients that used to be in motor oil when it stuck to the metal and you were able to change your oil twice a year.

Iron is more of what you are buying with the acid treatments will end up white to white gray. Zinc is heavier and if you are not painting it right away, actually needs to be coated with oil and is darker gray. And yes, it is always a goal in the industry to get these chemicals to work at lower temperatures since energy to heat is money. Most of what you can get a hold of outside of the chemical industry are cleaners and coating agents that were closer to the start of this deal.

I can pretty much guarantee that ecoat we see, (yeah, its e for epoxy) is epoxy. Newer acrylics are just more expensive.
 
is there a car involved in all this somewhere ?

Page 1 I think.
Reason I don't like chemicals for removing rust on something I'm painting. Interesting 'read though.
No 'easy way out' if you want it Right. Although They keep trying. Lacquer thinner don't lie.
 
After waiting 4days for epoxy to cure I can say I have no issue with the m2m or epoxy that I just did this week. Frame was media blasted prior.
 
shine said:
is there a car involved in all this somewhere ?
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If you follow along, we were discussing how new manufacturing includes chemical cleaning and the general consensus of the experts here wanting to just repair on scratched bare metal. I think you commonly refer to this technology as "snake oil". The new manufacturers are using the industrial type of pretreatment on their steel, so I thought maybe, possibly, someone with an open mind would like to learn something.
 
mtm will gain you nothing unless you coat with an aluminum paint. it is no stronger , no more water resistant . all fillers are polyester resin with fill.
the best filler out there is evercoat vpa .
 
shine said:
mtm will gain you nothing unless you coat with an aluminum paint. it is no stronger , no more water resistant . all fillers are polyester resin with fill.
the best filler out there is evercoat vpa .
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I thought one of the advantages of M2M over regular filler (beside increased compressive strength) was that regular filler was talc based (porous) and M2M was not, making it more waterproof like a fiberglass filler would be. ?
 
When the metal has a continuous film of epoxy over it, the need for a waterproof filler is eliminated. It's been my experience that all polyester fillers are porous to some degree. If you weigh a chunk of reacted M2M, then soak it in water for a week and re-weigh it, it will weigh more than when you started. Using epoxy ensures that no moisture will reach the metal, no matter what is used next, be it filler, 2K urethane primer, or polyester primer, which btw all tend to be porous to a certain degree. This is why we also recommend that any metal cut-throughs be re-primed with epoxy before more filler or primer is applied, this helps maintain that continuous film of waterproof epoxy over the metal.
 
no filler is waterproof .
m2m was all the rage in the 60's. sold as rust repair kits with screen wire and a spreader. it sells .... they still make it .
 
I like newspaper myself LOL. For the new one's out there, don't fall victim to the crap these companies lie about they are only looking to make a buck off of your back and don't care about your job you are doing or how long it lasts in fact they don't want it to last so you have to buy more of their crap to fix it after they told you, you did something wrong.

Barry is the one and only true exception to that rule I can personally think of who owns the product he sells and wants nothing but the best longest lasting results waring his product.
 
M2M is crap...... did I say that already??? Think about what you are using and how and where you are appling it. All metal is the same crap, fine alum in the puddy with a liquid hardner that has an acid of sorts (I think) you put that on and it is as strong as the metal around it and you can say that my work is all metal no bondo in there no way.... B.S.!!! That is what they want you to have planted in your head, your lying to yourself if you truly believe any of their B.S...

Think about it for a minute have you ever seen what happens to steel that touches alum.? Have you ever tried to take an antenna nut off a fender how about a wiper arm after it's been on for awhile.... Think before using the products from the gifted mouth of a horses ass salesman or believing the lies of a marketing asshat.
 
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