Epoxy paint lacking adhesion

[Ingleberry]

I think Jotamastic too thick for top side hence tried thinning out because the panel gaps ,shuts and trim tolerances are very tight considering car was hand built in 60's

Anyway very happy with Jotamastic without thinners done underside and engine bay at standard 6:1 ratio went off today ready for primer and paint i guess or should i wait full 7 days?

 

[steveo3002]

its no thicker than a coat of high build

you can blast it with jota , same day put a coat of high build on then it cross links and all bonds together nicley

 

[Weldinator]

Did you use summer or winter hardener?

I waited 3 days before applying the 2k paint onto the 87. Jotun said themselves, 3 days drying time is the ideal time for it to flash off well before the 2k paint is applied, summer hardener of course.

Have you given them a ring and ask your questions to get answers from the horses mouth so to speak ?

Best to ask them instead of here tbh, saves time etc.

Oh and Jotun is used on bridges, boats an a like, as said, please read the technical sheet i posted fully before asking any more questions. Then call them and you will get the correct answers.

http://www.jotun.com/Jotun/Paints/20020020.nsf/wvwProductDatabase/8B7ADD42CF64641DC1256A6B0043EE55/$file/TDS%20-%20Jotamastic%2087%20-%20English%20(uk)%20-%20Issued.21.12.2011.pdf

 

[Chipper]

I do same as Steveo, paint over while it's tacky or softish i.e. next day, for better bonding. There's no need to ring up Jotun, enough people on here have experience of it. And flashing is when the solvent's evaporated... that ought to be well inside of 3 days..
Jotun sprays nicely with just a little thinners, lays very evenly and can be built up quickly, if you can spray underneath that is.
Ingleberry what's the car? Sounds interesting. Aston or something Italian..?

 

[Weldinator]

Steveo said same day, i would not do it same day.

So what your saying is Jotun dont know their products better than anyone else then ?

After 3 days mine was still soft and has gained excellent adhesion with no flash of problems, which you may get painting on top of 87 the same day or next. Jotun said as long as another paint is applied before it fully cures ie within 7 days is fine. So i decided 3 days in, is more then inbetween the full 7 days.

There is only so much adhesion you can get, mine just wont come of by hand using a chisel, but it is 2k paint on top of 87.

As said, fully read the tech sheet then if you have anymore questions give them a call, they know their product better than any of us lot.

As your car is a 60's car, maybe some lead is present or something else with it being an old car ?

 

[langy]

Steveo said same day, i would not do it same day.

So what your saying is Jotun dont know their products better than anyone else then ?

After 3 days mine was still soft and has gained excellent adhesion with no flash of problems, which you may get painting on top of 87 the same day or next. Jotun said as long as another paint is applied before it fully cures ie within 7 days is fine. So i decided 3 days in, is more then inbetween the full 7 days.

There is only so much adhesion you can get, mine just wont come of by hand using a chisel, but it is 2k paint on top of 87.

As said, fully read the tech sheet then if you have anymore questions give them a call, they know their product better than any of us lot.

As your car is a 60's car, maybe some lead is present or something else with it being an old car ?

Whats lead got to do with it ???

 

[keithski122]

Whats lead got to do with it ???

Was that Tina Turner?

 

[Championship White]

Was that Tina Turner?

Haha, that was good!

 

[Ingleberry]

yes a lot of lead in the car all seams joins and detailing are lead braised.

The problem is the paint which says will bond with every type of metal yet doesn't. I presume majority of people professional or not painters once primers on if no reactions everyone carries on. The bonding to substrate is never tested (i only found out by accident) otherwise like everyone else I would have continued with painting top coats.

Can Jota be applied and bonds over top of traditional 1k cellulose Zinc Phosphate and Micaceous Iron Oxide anti corrosion primers, since advised encasing metal in plastic doesn't stop existing rust and epoxy anti corrosive properties are good for new or highly prepaired blasted metal?

 

[steveo3002]

sounds like youve just made some mistakes somewhere along the line

jota or any decent epoxy should be ideal for the job and will go over lead no probs

it would go over 1k products but i see no point , you want the good stuff (whatever you decide is best) in direct contact with the clean metal, not sitting on top of various random layers of stuff..thats when things crack and have issues

 

[Chipper]

What I'm saying Weldinator, is that you've used the stuff once, very recently yet you feel able to offer advice despite clearly not having much of a clue about this stuff or paint in general, as is evident from your many questions and posts in the past. And then you tell the OP not to ask any more questions which is pretty rude imo. We don't all need to phone the manufacturer as you seem to.

Ingleberry, Jotamastic is under my last two cars and just put some on a chop I'm painting. Minx used daily, rough roads round here with lots of stones and gravel, no chips underneath at all, unlike the topside. My Landy is still sound, used it daily for a year and now is living in a Swedish forest now where the current owner says it's all good still.

It should grip wherever it has a good mechanical grip. Celly is a weak base for it imho, I've done that but only inside the boot where it doesn't matter. Can't speak for the other paints, wouldn't use it that way anyway, it's best on metal. Haven't found fault it with it yet.

 

[REv]

Got me worried!!

4/5 days ago I did the inside of a couple of very old MG front wings with Rustbusters 121. preped with Knotted wire wheel and 40 grit disc. All seems OK, definately can't pick off with fingernail!! got to be quite sharp chisel or knife, bit like trying to scatch formica/old type kitchen worktop. Have you spoken with the boss at Rustbusters? Always been very very heplful with me on any queries and tinting of pimers etc.

 

[Ingleberry]

What I'm saying Weldinator, is that you've used the stuff once, very recently yet you feel able to offer advice despite clearly not having much of a clue about this stuff or paint in general, as is evident from your many questions and posts in the past. And then you tell the OP not to ask any more questions which is pretty rude imo. We don't all need to phone the manufacturer as you seem to.

Ingleberry, Jotamastic is under my last two cars and just put some on a chop I'm painting. Minx used daily, rough roads round here with lots of stones and gravel, no chips underneath at all, unlike the topside. My Landy is still sound, used it daily for a year and now is living in a Swedish forest now where the current owner says it's all good still.

It should grip wherever it has a good mechanical grip. Celly is a weak base for it imho, I've done that but only inside the boot where it doesn't matter. Can't speak for the other paints, wouldn't use it that way anyway, it's best on metal. Haven't found fault it with it yet.

I find end user experiences just as valuable as manufactures themselves, already done underside with jotamastic upol gravitex and 10 coats of celly which seems just as good as the old fashioned ways only time will tell if any better.

Its top side that concerns me because Jota doesn't have any anti corrosive elements hence question about applying over Zinc Phosphate and Micaceous Iron Oxide primers to treat the existing surface rust which i know works reliably from previous experience.

 

[Ingleberry]

4/5 days ago I did the inside of a couple of very old MG front wings with Rustbusters 121. preped with Knotted wire wheel and 40 grit disc. All seems OK, definately can't pick off with fingernail!! got to be quite sharp chisel or knife, bit like trying to scatch formica/old type kitchen worktop. Have you spoken with the boss at Rustbusters? Always been very very heplful with me on any queries and tinting of pimers etc.

Yes i tried the boss was unhelpful despite buying hundreds of pounds more stuff from them the second time round didn't want to know when it failed.

Later learned equal number of unhappy responses of rust comming through WITHIN a year with those who were happy. I now seen examples where its failed in person from few various people inc professional bodyshops having to re do work under warrenty at own expense like myself.

 

[Weldinator]

Not much of a clue about paint, yeah right ok then if you say so. I wasn't being rude, i was trying to advise him the quickest and easiest way to get the info, im really not sure why you think asking them is wrong and asking here is better. They gave me advice that no one else could, i didn't need to ask them, i thought it best too, so no mistakes are made using a product ive never used before like this poster here.

Again none of you lot know more than Jotun and saying otherwise shows how much you know about their paints no matter how many times you have used it. I have used it more than once on other things for your information.

Most of these questions are in the tech sheet, i rang them myself because i got different opinions on the stuff and had not read the tech sheet. Jotuns advice was different to everyone else's, again this shows me i was doing the right thing asking them for certain advice. Not that everyone else was totally wrong.


You say better adhesion, well my 3 days was more than enough, again you can only get a max amount of adhesion and i got it doing it the Jotun way. Some say better to rid all the rust yet Jotun is surface tolerant, used on Bridges and boats.

Everyone using it has a different situations, ie cars, paints, temps, atmospheres etc etc. Im not saying asking here is a waste of time just checking the tech sheet is a good start. I made the mistake by not doing this myself, wasting time posting when the tech sheet had almost all the answers i needed.

When i rang them i got all the info i asked and they were very happy doing so, not sure why ringing them is a bad thing unless you got a bad adviser or something.

 

[PhillipM]

This would be the same data sheet that says recoating for maximum bonding is fine within a couple of hours then?

 

[steveo3002]

.

Its top side that concerns me because Jota doesn't have any anti corrosive elements

from thier own site...

Gives excellent corrosion protection both in salt and fresh water

epoxys are about as good as it gets , sounds like youve decided on something 1k anyway

 

[langy]

Well heres an end user opinion for you, I've used Lechlar Epoxy primer for the last 25 years on a fair few cars, I've never had any epoxy peel or lift, I still know of all the cars and they are still perfect.
I've never used the Jotun and never will because ive never had a problem so no need to change.

 

[Ingleberry]

Well heres an end user opinion for you, I've used Lechlar Epoxy primer for the last 25 years on a fair few cars, I've never had any epoxy peel or lift, I still know of all the cars and they are still perfect.
I've never used the Jotun and never will because ive never had a problem so no need to change.

I went with Lechlar today all over the top side on bare metal without etch primer as you said before, seemed like best stuff out the bunch of epoxy paints along with Jota that i tried.

Got loads of full tins of paint that are good for nothing, might do the shed lol

 

[Ingleberry]

from thier own site...

Gives excellent corrosion protection both in salt and fresh water

epoxys are about as good as it gets , sounds like youve decided on something 1k anyway

i'm not 100% sold on epoxy from my own trials on basis they really need blast cleaned totally rust free to work and bond well.

Jota Lechler and Glasruit epoxy seemed most forgiving and stuck through surface rust and clean metal alike in uniform way, others were patchy at best.