Paint cracking

[bossy122]

I didn't clear the 4/9 and I don't use TS13 when I do clear. Unfortunatley, for TS36 to work, you must use 3 to 5 coats to build up the color. I usually spray the coats at 5 minute intervals as the piece sits in a 90° garage. I do that so quick to try and minimize the thickness seam of the red.
I've been looking for an alternative for a while that doesn't need 5 coats. I have something called Gaia color 103, anyone used it before?

[bossy122]

This rear wing is on my oldest or 2nd to oldest Mac, a good 10 years old. I would swear I took some pics of this car within the last 2 years and it wasn't like that. The room it is stored in gets fairly warm in the summer and I wonder how much heat might play a role in this problem.

[phicks]

Have heard these horror stories about TS-13 for years which is why I avoid using it. I use Mr. Hobby Super Clear gloss
coat . Never had any of those issues and put it over Tamiya and Mr. Color . Great stuff , cures rock hard too.

[AJP01]

This is really disappointing and frustrating on so many levels. We work so hard to try and get good surface prep, primer, masking, color coats, etc., and then to have something crack or bleed at a late stage is my nightmare. I'm sorry you're having to go through it.

AJ

[PeteJ]

Petej, would you consider 20 minutes enough time for a single THIN coat to cure? I have usually left only 5 minutes max between coats with Testors, sometimes less. I leave the thick coat for last, and at that, it is just wet to the eye, not sopping wet. If that makes sense.

That is pushing it to much for me. If I am building up layers of the same paint then I use 30 to 45 minutes per coat. As I mentioned I like to put fresh paint in my food dehydrator. At 130 degrees F, it really helps it cure much faster. If is a different color or clearcoat, over night, in a food dehydrator if possible. Since I started using the dehydrator for everything, I have rarely had any paint issues.

Also, just to be clear, a thin coat is one that doesn't cover the base coat with one pass. I generally figure coverage starts to get close after the third coat.

[bossy122]

Petej, would you consider 20 minutes enough time for a single THIN coat to cure? I have usually left only 5 minutes max between coats with Testors, sometimes less. I leave the thick coat for last, and at that, it is just wet to the eye, not sopping wet. If that makes sense.

That is pushing it to much for me. If I am building up layers of the same paint then I use 30 to 45 minutes per coat. As I mentioned I like to put fresh paint in my food dehydrator. At 130 degrees F, it really helps it cure much faster. If is a different color or clearcoat, over night, in a food dehydrator if possible. Since I started using the dehydrator for everything, I have rarely had any paint issues.

Also, just to be clear, a thin coat is one that doesn't cover the base coat with one pass. I generally figure coverage starts to get close after the third coat.

How do you treat thick seam lines from the masking tape?

[fastbackfreddie]

Yep, I had this problem many years ago with the MP4/4. Flouro cracked, white unaffected.
Welcome to the group.
Having said that, it hasn't deteriorated any further in 22 years. It took mine probably about 12months to show.
I painted the MP4/5B exactly same method and 20 years on, still perfect. Go figure!

[Corpsegrinder]

Sorry to hear about such nightmare! I have two Macs done with Tamiya white primer, TS-26, TS-36 and TS-13 all from rattle cans. The first one was done 5 years ago and the paint is still OK, the other one almost 3 years also all good so far. Between each color I usually wait one week or more. On my next McLaren I will try to replace TS-36 with a RAL 3024 made from my local hardware store. Hope it'll go well.

[PeteJ]

Petej, would you consider 20 minutes enough time for a single THIN coat to cure? I have usually left only 5 minutes max between coats with Testors, sometimes less. I leave the thick coat for last, and at that, it is just wet to the eye, not sopping wet. If that makes sense.

That is pushing it to much for me. If I am building up layers of the same paint then I use 30 to 45 minutes per coat. As I mentioned I like to put fresh paint in my food dehydrator. At 130 degrees F, it really helps it cure much faster. If is a different color or clearcoat, over night, in a food dehydrator if possible. Since I started using the dehydrator for everything, I have rarely had any paint issues.

Also, just to be clear, a thin coat is one that doesn't cover the base coat with one pass. I generally figure coverage starts to get close after the third coat.

How do you treat thick seam lines from the masking tape?

I have some sanding sticks from Micro Mesh that are a 12000 grit. A couple of passes and it cuts down the edge and go from there. It takes some practice and a delicate hand. Oh and here is the site for the Micro Mesh manufacture. I prefer to deal direct and avoid the "hobby" markup. https://micro-surface.com/index.php/mic ... uffer.html

This shows a tri grit stick, but you can call and get single grit. I prefer the single grit, because I fined I will use up one grit faster than the other grits on stick and wind up with a bunch of partially used one around. However for the first time they may be a good choice because you can see how each grit works.

They use to let you order just a few. I got in the habit of ordering them in lots of 50 or 100. That of course lasts me for years, but I get what I want.

[Sennafan]

I don’t clear TS36, but I won’t use again

The combination I have seen is over Tamiya primer on resin white metal and PE

My plastics with 36 are all fine

But my MFH 4/4, 4/5b, 4/8 are all cracked, used Testors flouro on 4/7