need help with DP specs

[Blaubus]

using PPG DPLF and the DP402LF hardener, does anyone know the time to full cure at 70F? (Not looking for guesses- the reason should be obvious.)

Yes, i did check the PPG tech sheet, and it doesnt say. I usually assume 16 hours (topcoat cure), but there high build primers cure in 4 hours, and it made me wonder if epoxy cures faster than topcoat...

one thing that annoys me about PPG tech sheets is that they often tell you how long till the application of other materials, but not how long to full cure- as if we all want to maintain the heat in our garages to 70F on winter nights...

perhaps PPG has stock in big oil?

[buguy]

To topcoat:
1 coat = 30 min
2 coats = 60 min

To apply body filler:
1 coat = 1 hour
2 coats = overnight

Can be topcoated within 7 days before you have to sand it before recoat.

[Blaubus]

yeah, all that is on the spec sheet bug guy, but none of those times are full cure. anyway, thanks for the reply.

[4xmike]

Why exactly do you need full cure. DP is designed to be a sealer laid down before basecoat or single stage.

figure DP has an 8 hour pot life with 402 catalyst or 72 hour potlife if you use 401. it will take quite a bit of time for it to "cure".

I have had flaws in the sealer coat before and had to wait for DP to dry to sand out flaws, so I can say that if this is the case there is a way. If you have laid down light coats for sealer purposes give it about an hour to 2 hours and very lightly sand with 800 - 1000 grit wet. You will need to spot the area sanded with another shot of sealer. I usually will through some heat lamps on it if I am in a hurry. this still takes some time.

if you sprayed it as a primer and laid it down heavy plan on waiting a few days or more, especially if it is cold.
_________________
______________________________________
Past VW's
1965 Bug Sedan
1969 Square Back
1956 Oval Sedan
1965 Bug Sedan
Current VW's
1964 Bug

[buguy]

I agree. That is an epoxy primer that is to be topcoated before it cured to do what it was designed for. Thats why you are not finding fully cured times. Tryst me, you really want to avoid sanding epoxy....it isnt fun. I would at least get your high build on it asap.

If you are waiting because of flaws, I would recommend giving it at least a couple/few days. I guess if you need a definate answer I would say it is 7 days until it is fully cured, since that the time they give before you have to sand before topcoating. But like I said, that stuff sands like crap and clogs paper like no other, if you have a problem in it, do yourself a huge favor and spray a few coats of 2k primer over it, and do your sanding on that....its much easier. Plus then you wont have to sand it all down and reshoot it if you miss your recoat window.

[Blaubus]

i put 3 coats of K36 over it 1 hour after one thin coat was applied.

its my fault that the question has been misunderstood... my question is about when i can shut off the heat. i really chose the wrong word when i asked about "cure time." what i need to know is time to full catalyzation.

like most all paint products, DP has a hardener. full catalyzation occurs at different rates for different products. for example:

K36 + K201 takes 4 hours @ 70F. after that you can shut off the heat without the hardener failing to fully catalyze the primer.

DCC + DT870 + DCX61 takes 16 hours @ 70F after that you can shut off the heat without the hardener failing to fully catalyze the paint

so how long to fully catalyze the DPLF + DP402LF?

[buguy]

Thats really a difficult question. I would have to say that it would be seven days. I think if it was me...I wouldnt want to heat the garage for 7 damn days...but then again I would be the one responsible if something were to happen. So...to be damn sure, seven days... wanna take a chance..... maybe a few?

[Blaubus]

[Blaubus]

PPG says 24 hours at 70F to full catalyzation

[4xmike]

Even after this 24 hour time DP will still be soft. It is an excellent product, but I don't believe that its purpose is to be sanded. It will sand, but your paper may clog more than normal. I had laid down DP on a hood for a 32 ford I was painting to keep it from getting any flash rust on the surface and it still sanded soft a week later. Let us know how it goes.

Unless you are in extreme conditions, you shouldn't have to "bake" any paint. I am fortunate and live in AZ where even in the winter my garage doesn't go below 60, so unless I am in a rush I don't cook any of my paint jobs. However, I do have to cool my shop in the summer to keep it in the 80's when I am spraying. I have had primers catalyze in my gun in the summers before.

Good luck.
_________________
______________________________________
Past VW's
1965 Bug Sedan
1969 Square Back
1956 Oval Sedan
1965 Bug Sedan
Current VW's
1964 Bug

[buguy]

Please post your findings.....cuz thanks to you...im now curious!

[Blaubus]

i kept it at 70-75 for 16 hours only, so imagine it might be a bit soft when i sand. i will report back. as for 7 days full cure, that requires that solvents evaporate. so temps during those 7 days, as well as flash off between coats during the spray and thickness of coats matters for that, as does the use of the correct reducer.

funny thing happened when i talked to the PPG rep today- as we discussed all the different PPG catalysts, he admitted that PPG tells people that 60F is the absolute minimum even though the catalysts still work down to 55F.

i asked him why that info wasnt consistent with what other reps have said in the past. he told me that most people will try to cheat the recommended temp a few more degrees, assuming they will be safe. so PPG makes it safe by misleading them for their own good. additionally, he mentioned what i already know- that in a heated garage this time of year, the metal is colder than the air temp. that extra 5 degrees covers that difference.

[buguy]

That is typical of most comsumer products. Plus, you really dont want to be on the ragged edge anyway. I think I would have kept it heated longer than 16 hours though!

[Blaubus]

yeah, i am not feeling too great about the 16 hour decision, but its already done, so i cant worry about it. just gonna wait and see if the paint falls off the car someday there is no way i will go back to metal again just to get it right- for all i know, it may be fine.

[buguy]

Yup....you never know....may last you a lifetime.