Paint problem

[Mike_G]

I have yet to find a paint that affects well-cured Plasti-Kote automotive sandable primer, including uber-hot R/C car lacquer

[StevenGuthmiller]

Sounds like you've got all the bases covered!

I've had my share of trial & error. This system works pretty well for me anyway.

Steve

[Ace-Garageguy]

I have yet to find a paint that affects well-cured Plasti-Kote automotive sandable primer, including uber-hot R/C car lacquer

That's helpful. I've been meaning to do some back-to-back tests with PlastiKote and Duplicolor primers.

Define "well-cured" please. A couple days? A week? more?

[Ace-Garageguy]

I'm not so sure... I've seen these patterns in the bare plastic -

Yes, you have.

These irregularities are the result of uneven or jerky mold filling when the parts are being made.

Trust me on this. It's true.

When the solvents in the paint or primer hit these irregularities in plastic density, they amplify their appearance because they don't attack the entire surface exactly the same way.

Really.

Edited April 8, 2015 by Ace-Garageguy

[Mike_G]

That's helpful. I've been meaning to do some back-to-back tests with PlastiKote and Duplicolor primers.

Define "well-cured" please. A couple days? A week? more?

For me, a lot longer- I tend to work very sporadically so sometimes a primed, wet-sanded body will sit on my bench for a month or more.

That's not to say that I think it needs that long, I think a week would probably be fine

I used Duplicolor clear over R/C car lacquer on this Merc:

[fseva]

Yes, you have.

These irregularities are the result of uneven or jerky mold filling when the parts are being made.

Trust me on this. It's true.

When the solvents in the paint or primer hit these irregularities in plastic density, they amplify their appearance because they don't attack the entire surface exactly the same way.

Really.

Oh, it definitely sounds logical - no argument here...

[fseva]

I used Duplicolor clear over R/C car lacquer on this Merc:

What is this R/C car lacquer? I have used Spaz Stix, which is used on radio controlled cars... is that the type of thing you're referring to? I actually never thought of it as being a "hot" lacquer...?

[Mike_G]

What is this R/C car lacquer? I have used Spaz Stix, which is used on radio controlled cars... is that the type of thing you're referring to? I actually never thought of it as being a "hot" lacquer...?

I have a box full of old 2/3oz. bottles of Pactra R/C car paint that I used to paint slotcar bodies with. It's made to etch into the lexan and will craze the heck out of styrene.

[fseva]

I have a box full of old 2/3oz. bottles of Pactra R/C car paint that I used to paint slotcar bodies with. It's made to etch into the lexan and will craze the heck out of styrene.

Well, Spaz Stix is also formulated for lexan, and it works just fine on plastic car models! Maybe Pactra lexan/polycarbonate paint has been reforumulated - I haven't seen any warnings against its use on styrene...

Edited April 8, 2015 by fseva

[Mike_G]

Well, Spaz Stix is also formulated for lexan, and it works just fine on plastic car models! Maybe Pactra lexan/polycarbonate paint has been reforumulated - I haven't seen any warnings against its use on styrene...

The stuff I have is from the '80s and early '90s so there's a good chance it's been changed

There's no warning on it either, but it is definitely hot stuff. I use the old Pactra thinner for it too, it's very slow.

[fseva]

The stuff I have is from the '80s and early '90s so there's a good chance it's been changed

There's no warning on it either, but it is definitely hot stuff. I use the old Pactra thinner for it too, it's very slow.

As in... slow to dry? BTW, if you didn't have all these extra colors, what would you be looking to buy, now that the new owners of Testors have discontinued the Pactra line? It looks like Duratrax has stepped in with original forumulae, but they don't give any warnings either (I sent them an email to ask if their product could be safely used on styrene.)

[Mike_G]

As in... slow to dry? BTW, if you didn't have all these extra colors, what would you be looking to buy, now that the new owners of Testors have discontinued the Pactra line? It looks like Duratrax has stepped in with original forumulae, but they don't give any warnings either (I sent them an email to ask if their product could be safely used on styrene.)

Yes, slow to dry. I think that's to give it more time to etch into the surface. I tried a faster lacquer thinner and it didn't work.

My LHS still has some of the older Pactra product on the rack and you can still find it on eBay, the stuff I have still has $1.79 price stickers