[1971BB427]

Things have come to a halt on the '39. I got all exterior light housings, and chrome off the car, and totally ready to shoot primer-sealer today. Then planned on painting it in a week or two whenever temps allowed. It was 73 degrees today, so perfect weather for my catalyst to work.
But I talked to my painter friend who shot my Austin gasser and asked how long after it was sealed did I have before painting? He said it should be painted as soon as the primer is either tack free, or almost fully dried. He added if it's OK to sand it, then it's already getting too late to paint!
Never heard this before, and have had some amateur painters tell me to wait for it to "gas out" which might take a week to happen. So I figured waiting longer wouldn't hurt, but my buddy's been painting a lot of high end show cars, so I trust his advice.
So now I'm waiting until the temps get better, and I can shoot primer-sealer, and multiple coats of finish paint, all in one day. Might take another month before I get a day where it's warm enough by around noon to get it all done in one day!
In the meantime I guess I'll continue to go over the body multiple times and really make sure everything is as good as possible.

 

[Custer55]

Always best to go by the technical data for the paint you are using. It should give you a recoat window to apply the topcoat over the sealer without having to sand it again.

 

[1971BB427]

Unfortunately it doesn't, or if it does it's written in code. I've found as a newb to painting that some terms used in the data don't make sense. Some make perfect sense like "time to recoat" of 15 min. But then it says "tape time" 2 hrs. which makes no sense to me? Does tape time mean when you can put tape on a newly painted surface? Or does it mean when you can remove tape after painting?
And another that says "sandable 2 hrs." appears to indicate when you can begin to sand out any flaws. Of course all these times are listed under air drying times, as a heated booth has accelerated times for every step.

When I go to youtube to look at videos, it gets more confusing. I can quickly eliminate the amateurs telling me what they did, as they have no input about how well the paint held up years later. And many are obviously doing a lot of things I cringe to even see! Guys painting over cars without the use of primers, or sealers before painting. And guys painting with all sorts of crude equipment. But even getting to guys who appear to be professionals, I didn't run into anyone emphasizing the importance of sealing the car, and then getting paint on it soon after. Or guys advising not to sand sealer before applying paint?
So the more I look at this, the more uncomfortable I get. I'm still planning to do it, but just backing off and waiting for more input so when I do, I know it's going to not be done incorrectly.

 

[nad427]

Geez that is confusing. An old painter guy showed me a couple pics once. In one the primer had a load of microscopic hairs for the paint to grab on to, in the other the hairs were sparse because it had say too long. Don’t remember the time span though. He told me though that he sanded every coat of everything to get an absolute flat surface and sand grooves for paint to grab on to before spraying paint. Made sense at the time, so I’ve done it that way ever since. Never have had any problems with that that I know of.

 

[1971BB427]

To make matters worse, a great number of places I've posed this question results in half the people telling me, "Read the data sheets". If somebody can read a data sheet with drying time, flash time, tape time, and figure out how long a primer can remain unpainted and still be good, they're either not talking, or are afraid to advise me.
I have Speedkote epoxy primer sealer SMR 260G on now, and Speedkote SMR 210 2K primer here as well.

https://s3.amazonaws.com/speedosds/TDS/SMR-210+SL+Tech.pdf

SMR-260G/261 2.1 VOC Epoxy DTM Primer/Sealer Gray

www.speedokote.com

The SMR 260G epoxy says it needs to be top coated within 3 days, or sanded prior to top coat if done after 3 days. So it appears to have a little more instructions than their 2k primer has.
So if I don't get some feedback, it seems like the best option is more epoxy primer, and then shoot paint within 72 hrs., or sand before shooting paint.

 

[blackwidow]

Here’s what I follow with my sealer..... tape window is just that if painting flames it could be masked to continue to build layers of color to make them or stripes if one prefers. I remove tape after last flash off. Still tacky but not grabby, keep some fine point tweezers near just in case something gets blown or drops .
When I spray I wait no longer than 12 hours even if it says I have 36 . Flash time varies and if I get a chance to spray whole job in one day I go anywhere between 15-30 minutes depending on temp in garage..... typically the way I spray is epoxy primer then 2 high builds with sanding between, then a reduced thin spray of primer to last check followed by 2 coats sealer then I let it set a few hours depending on temp outside then go right into paint. Not to critical but it’s like a concrete pour everyone seems edgy because it’s so important. If anything goes wrong just simply stop and regroup pretty forgiving sorta speak , Just watch ratios and reducers and pull that trigger.

 

[1971BB427]

View attachment 337175 View attachment 337176 View attachment 337177
Here’s what I follow with my sealer..... tape window is just that if painting flames it could be masked to continue to build layers of color to make them or stripes if one prefers. I remove tape after last flash off. Still tacky but not grabby, keep some fine point tweezers near just in case something gets blown or drops .
When I spray I wait no longer than 12 hours even if it says I have 36 . Flash time varies and if I get a chance to spray whole job in one day I go anywhere between 15-30 minutes depending on temp in garage..... typically the way I spray is epoxy primer then 2 high builds with sanding between, then a reduced thin spray of primer to last check followed by 2 coats sealer then I let it set a few hours depending on temp outside then go right into paint. Not to critical but it’s like a concrete pour everyone seems edgy because it’s so important. If anything goes wrong just simply stop and regroup pretty forgiving sorta speak , Just watch ratios and reducers and pull that trigger.

Thanks for the great advice! Sounds like a good way to go, and I'm definitely going to try to do everything in one day when I begin the prime and paint. Just hope I get the primer and sealer on smooth enough to not end up spending too much time sanding, and end up painting late in the day!

 

[Custer55]

If your going to use the epoxy as a sealer you should have up to 3 days after spraying that to top coat without sanding. The epoxy I have been using (Tamco) has a recoat window of 7 days without sanding. An epoxy that can be thinned out more to use as a sealer is a good choice as it gives you a longer recoat window and will adhere well to any small sand throughs to bare metal which is a big plus. You should be fine to spray on the speedkote epoxy as your sealer and just spray the top coat the next day if you run short on time. You could lightly scuff the sealer with scotchbrite also to aid adhesion if you wait untill the next day to spray the color. Not a bad idea to do that anyway as it will remove any small nibs or dust that may get in the sealer. Maroon scotchbrite is equal to about 320 to 400 grit sandpaper.

SCOTCHBRITE GRIT CHART
7445 - White pad, called Light Duty Cleansing - (1000)
7448 - Light Grey, called Ultra Fine Hand - (600-800)
6448 - Green, called Light Duty Hand Pad - (600)
7447 - Maroon pad, called General Purpose Hand - (320-400)
6444 - Brown pad, called Extra Duty Hand - (280-320)
7446 - Dark Grey pad, called Blending Pad (180-220)
7440 - Tan pad, called Heavy Duty Hand Pad - (120-150)

 

[1971BB427]

I have a friend whose son graduated Lincoln Tech Autobody school many years ago, and forgot all about this until a couple days ago. I called his son Dale and he stopped by on his way home yesterday to look at my paint project, and give me some advice.
He told me there are basically two schools of thought, and neither is wrong. It's just two different ways that paint is done, and they're referred to as the American way and the European way. In the US he said most people are more into production painting where time is important, so they do everything on a rapid basis. So often a sealer is laid down, and the same day, or the next morning paint is applied. In Europe they lay down primer, and let it shrink, and cure for several days to a week, and then they wet or dry sand with 500-800 grit, and then clean and lay down paint.
He said neither is wrong, but you can't do part of one, mixed with methods on the other. So he said I can shoot the Speedkote high build primer I have, instead and then allow it to cure, and come back later and shoot my top coat. I asked if I had a window of minimum/maximum time, and he said at least 3 days minimum, and better 5 days wait. But no such thing as a maximum as long as the vehicle stays inside, and isn't subject to dew, condensation, or moisture that might be absorbed by the primer.
So I will go ahead with the 2k primer the next warm 70 degree day, and then allow it to cure. Then when it's cured and we have another warm day, I'll arrange for him to come over and he said he'll "supervise" me as I lay down paint. He also said he just bought a new DeVilbiss plastic spray gun that he'll bring too, so I can spray it with a high quality gun. He said the DeVilbiss has plastic tips that get replaced after 3-4 dozen paint jobs, and then the gun is like new again after a new tip is changed. Guess this is the latest upgrade to professional spray guns, and he's been using one for a couple months now every day at work, and loves it.
Unfortunately our weather has been perfect for the last week, with 70 degrees highs every day. Now it's turning cooler, and no warm days in sight in the near future. So who knows when I'll even shoot primer again?

 

[1971BB427]

Why is it that stuff fails just when you're ready to use it again? It reminds me of the often overused phrase, "Ran when parked"!
I was working on the '39 and wanted to spray some more high build primer on a couple panels. So I grab my primer, and mix in the catalyst and some reducer. Stir it all up, and dump it in my spray gun. Turn around to do a test spray on an old piece of plywood leaning against the wall and it dribbles out the end of the nozzle!
I dumped the primer back in the mixing cup, and quickly tore the gun apart to see if I could do a quick cleanup. But after pouring some reducer in the gun to check the pattern, it still just dribbled out the end. Threw my stuff down, and raced over to Harbor freight, and bought a spare spray gun. Didn't want a cheap $15 gun, but didn't need a $175, or $275 they sell either. So settled on a mid grade gun I figured would spray primer OK. Rushed back home, and wrenched the connectors, and inline regulator off, and transferred it all to the new gun. Shot some acetone through it quick to clean it, and loaded up the primer and sprayed before it turned over.
Was actually surprised at how well the new spray gun shot primer! Good enough I'll use it when I spray the whole car in primer later.

 

[Custer55]

Murphy's law in action "Anything that can go wrong will go wrong at the worst possible time"
I actually use the cheapest gun HF sells for primer and it works just fine for primer and epoxy.

 

[55Madman]

DOH!!!!!

 

[blackwidow]

Yes that’s a gross feeling! I’ve been using the dekups system when I spray, it allows quick loading of paint in their thin cups then transfer to gun as a mess free system with minimal waste. After I spray color through I clean them out with reducer through whole gun and they go to the primer shelf for one spray only then trash. Then knock gun down and soak tip and flush gun.

Having a similar issue as yourself I then chose to get a separate gun for primer and color and I use the harbor test my fate guns on epoxy style and just call it a loss to remain stress free.....

 

[busterwivell]

Had a similar issue, gun loaded, ready to spray, and the Lowe's Compressor locks up.

 

[1971BB427]

The gun that didn't work was a brand new $15 HF gun. Took it out of the box just for this job, and no good right off. I wont mess with trying to figure it out, or return it as the frustration wont be worth the cost of the gun.
The new-new HF upper end gun is a very nice gun, and sprayed beautifully. I'll use it when I paint too, and hope it does as well as it did yesterday.

 

[1971BB427]

Got sidetracked yesterday. Granddaughter called to say she had her first car accident. We gave her the wife's old '97 Mazda that I had just put struts, axles, and a new timing belt on. Only 125000 miles, and a nice little car for her. At least it was! She crunched one front fender, headlight, turn signal light, and scraped the urethane bumper a little.
So this morning I hit the local U Pull It yard and pulled a good fender, and lights off a '98. Brown instead of navy blue, so I sanded it and rattle can sprayed it before taking the old fender off. Then let it dry while I removed the fender. The fenders came off easy, but her crunch bent the end of the inner fender support at the end. So grabbed a 24" pair of channel locks, and persuaded it back into shape. then using a pair of hammers, I finished banging it into position so it fit the new fender when I test fitted it.
Her little crunch popped all 8 of the little plastic fasteners that hold inner fender to outer fender, so I bolted the urethane bumper to the fender, and put a couple snap in plugs and screws in the inner fender until the replacement fasteners can get here. At least she can drive it to work now.
Going to have to find a better paint match later, as the color I grabbed was the darkest blue, and still not as dark as her car.
But at least this project didn't sidetrack me long from my own fun!

 

[blackwidow]

It happens ! At least she’s ok! Personally I like being sidetracked it allows my eyes to catch something I was potentially going to miss or something I wasn’t happy with and have a second chance to correct it.

 

[1971BB427]

As soon as I shot the primer and cleaned up, I looked the '39 over and saw a few little spots where it needs a little more work. So I will have to take care of those spots this week, and then I can address paint work. Supposed to be great weather this weekend, but not sure I'll be ready, so might not get to paint in the next window.

 

[1971BB427]

After a few more little defects I found and fixed, I think I'm finally ready to squirt some paint! And by chance spring has really hit here too! I did a little sanding in the jams, and doors, and masked the interior and trunk off today. So with weather supposed to be high 60's to high 70's the next week, I'll shoot all the jams tomorrow. Then once it sets up, I'll close it all up, and sand the whole car with 500 grit, and paint the exterior on Wed. I hope.
I had to remove the rear slicks today to allow more clearance to ensure I get the fender lips shot around the radius and not have the tires in the way. I think I'm as ready as can be, and weather is good; so might as well take the leap!

 

[1971BB427]

Got the jams shot this morning. Temps are slightly low, but my friend's son told me slightly low isn't a problem like too hot is, and he prefers to shoot color slightly below the catalyst range. Anyway, it went fine, and no runs so far. Did the door jams, inside of trunk lid, and doors inside edges only.
I'll remove some masking later so the doors close, and then sand the whole car one more time tomorrow prior to starting the final paint work. The Wimbledon White is a little creamier than I thought, but I'm glad it is. Better than a stark white, that's a bit too bright.
The new spray gun is still spraying really great! And the urethane lays down much better than the primer did!