Do you sand before clear coat?

[Lowpuller]

If so why?

What grit?

I am using lacquer.

Thanks



So many rockets, so little time, and money.

 

[FredA]

No...
But you need to read your CC instructions.

We shoot Valspar automotive paints.
You need to sand between coats only if you waited more than 24hrs since the last coat.
Quicker coat cycles don't require sanding -- in fact it's not recommended.

YMMV depending on your clear.

 

[Maxx Mayhem]

I use PPG on a car. The clear serves as the curative in a BCCC application. Single stage requires a hardener. Over a base, shoot 1 light and 2 wet coats of clear. Then you have something to sand. Usually for rockets though, (LPR) I try to get the primer perfect, shoot color with an airbrush, then a light coat or 2 of lacquer. Done.

 

[wfcook]

Sorry for my ignorance, but what do PPG and BCCC stand for?


Sent from my iPhone using Rocketry Forum

 

[VonMises]

It depends on the type of paint and is it's needed or not.

When I do wet sand paint before clearcoat, it's 1500 or 2000 grit. Again this depends on the type of paint.

 

[G_T]

I've typically misted on a first coat of clearcoat before the preceeding color layer has fully dried. Therefore it can bond well... Then spray on a couple thicker coats of clear before that is fully set. For the last coat, I spray enough to flow out the surface but not quite enough to make it run.

A little practice helps, but this usually works fairly well - even with rattle cans, provided the rocket is small. A rattle can doesn't put out enough paint quickly enough for large rockets. The overspray lands on areas that are surface drying, so the smooth flowed surface gets messed up. 54mm rockets are not a problem. Beyond 4" is certainly a problem! HVLP is much better for paint and clearcoat delivery then.

Gerald

 

[Nathan]

I have never found it necessary to sand lacquer before clear coat. With enamel I usually just wet sand it with 2000 grit and then polish without applying clear coat. When I do spray clear over enamel, I usually wet sand the enamel color coat first.

And I always wet sand the clear coat with 2000 grit, and polish.

 

[hball55]

For the last coat, I spray enough to flow out the surface but not quite enough to make it run.
Gerald

Is that what is referred to as "maintaining a wet edge?"

 

[Lowpuller]

I am using a testors silver metal flake as one of the colors. It looks and feels rough.

I am also using testors black metal flake it is smooth and pretty glossy.

I have used several cans of the silver on different rockets with the same result.


So many rockets, so little time, and money.

 

[dward]

Sorry for my ignorance, but what do PPG and BCCC stand for?


Sent from my iPhone using Rocketry Forum

PPG is a brand of paint. I assume he's talking about a 2K (2 part, the paint and the hardener) urethane paint. On a car it makes perfect sense. On a rocket it would be a major overkill, and an expensive one. I assume BCCC means base coat, followed by three coats of color.

 

[Micromeister]

I do not apply clear coating anymore.

I do Finish wet sand 600 to 2000grit some surfaces then use Perfectit-III and Finessit-II to remove imperfections and Polish the applied Paint after giving them a week or so to completely harden. After Decaling, it's a coat or two of Nu-Finish Polymer to add additional Shine if desired.

Rattle Can Clear Coats by their chemistry do not protect the paint, decals or vinyl graphics under them. They become quite brittle as they harden causing more damage from Landings and handling then a couple decent coats of Auto Wax.

 

[JoeG]

BCCC means Base Coat Clear Coat PPG used top stand for Pittsburgh Paint Group. Now I think it is the legal name of the company.

 

[hornet driver]

If so why?

What grit?

I am using lacquer.

Thanks



So many rockets, so little time, and money.

At least for me , the short answer is no---The extended answer is sometimes. If the base coat is a metallic-then absolutely not--if you have trash in a solid color it's ok to let it dry and sand. I tend to lay clear over the color coat as quickly as possible--as in right after I spray the color. Remember, laquers-like all paints--continue to dry and shrink over time. One advantage to clear coating--you can sand and polish the clear--That said, you'll get a beautiful rocket for a lot of work and beat it to death in pretty short order. So you have to weigh your options. I always figure the first flight will be the best the rocket will ever look--so what the hell--make it shine !!!---oh yea, If I wet sand the color coat I usually use 600 grit wet/dry. It gives enough physical bond to do the job.

 

[TopRamen]

No, not after my Paint is on, I just look for Dust or Pets Fur. Wish my Compressor still worked so I could blast them before Painting, but I make do, and don't beat myself up too much.

 

[Winston]

Not about sanding, but the clear coat, I like this:

https://www.rocketryforum.com/showthread.php?23500-A-primer-on-Future-Floor-Wax-usage

I use by volume 2/3 Pledge Care Tile & Vinyl Floor Finish with Future Shine and 1/3 cheap, blue automobile windshield wiper fluid (dilutes the wax and contains surfactants to promote flow). Spray it on with a window cleaner type atomizer, brush it down with a foam paintbrush until it begins to thicken. Very forgiving, self-distributes to prevent dried-in runs, looks fantastic, doesn't yellow. Use low-tack tape around the base of the nosecone (the portion meant to be inside the body tube) to elevate it out of the body tube, otherwise the thin wax could migrate into the area between the nose cone and body tube and glue it in place.

Water-slide decals can bunch up very slightly around their edges, but can be carefully pressed/rubbed down before the wax dries. All wrinkles disappear with drying, at least in my experience. There's no such effect on vinyl decals and the wax does a great job of sealing down and protecting both types. Any scuffs can be buffed out.

Automobile windshield cleaner typically contain methanol which is not good to inhale. However, I've always done this indoors to prevent problems wind-carried dust and it's had no obvious effect on me during or after.

 

[kenstarr]

Really depends. With airbrushing I've not sanded. Same with lacquers. I have sanded to cut off raised edges from masking when the paint is high build like most rattle cans put out.
-Ken

 

[Angel_of_the_Skies]

I have never found it necessary to sand lacquer before clear coat. With enamel I usually just wet sand it with 2000 grit and then polish without applying clear coat. When I do spray clear over enamel, I usually wet sand the enamel color coat first.

And I always wet sand the clear coat with 2000 grit, and polish.

Nathan, with floss colors I’ve had a hard time sanding away the orange peel as once I get to the low spots, I tend to get very close to the primer coat. I use 1000 and 1500 grit for enamel gloss coats

Do you suggest sanding till smooth? Sanding till all orange peel is gone? Switch to flat colors? I would appreciate your input, TIA!

 

[ep29030]

For rattle can clear coats my practice has been not sand the color coat, but to apply a clear coat, let it dry at least 24 hours, then lightly wet sand with 1000 grit wet paper. This helps to level the paint by knocking off the high spots. You can sand after every clear coat if you choose. If you sand after the final clear, you’ll need to use a wax to get a shine again. Or just skip sanding the final clear coat and enjoy.

 

[Rocketjunkie]

Don't clear coat. The only time I use clear is for colored fiberglass tubes and don't sand them either. However, I'm one that thinks 'if it looks good on the pad' it's good enough.

 

[Angel_of_the_Skies]

For rattle can clear coats my practice has been not sand the color coat, but to apply a clear coat, let it dry at least 24 hours, then lightly wet sand with 1000 grit wet paper.

My issue has been trying to get all and I mean ALL the low spots sanded. Since the paint was rustoleum white gloss, the low spots are very visible and glossy

I’ve had issues sanding to close to the primer coats that you can see the shade of gray

From my knowledge, enamel should be spray more than three coats do to it being prone to runs

This helps to level the paint by knocking off the high spots. You can sand after every clear coat if you choose. If you sand after the final clear, you’ll need to use a wax to get a shine again. Or just skip sanding the final clear coat and enjoy.

Noted

 

[Angel_of_the_Skies]

Don't clear coat. The only time I use clear is for colored fiberglass tubes and don't sand them either. However, I'm one that thinks 'if it looks good on the pad' it's good enough.

I try to be this way, but I’m a perfectionist. I guess that’s my downfall

 

[Angel_of_the_Skies]

BTW I use 1000 grit to get most orange peel sanded and 1500 grit to get the remaining

 

[ep29030]

I don't clear coat my rockets for the most part unless I have decals. Then I do it because the clear helps to protect and seal them. 2-3 clear coats with light sanding between coats can make decals disappear into the color coat. Well, except the heavy peel and stick ones. Even then you can smooth out the bumps with clear coat.

 

[FredA]

Don't clear coat.

Clear is pretty much required by today's automotive paints.
It provides the UV protection.
Your paint will fade without clear.

Rattle-can stuff probably needs it too - not sure - once you shoot automotive paint, you'll not use RC paint again.

 

[Rocketjunkie]

Clear is pretty much required by today's automotive paints.
It provides the UV protection.
Your paint will fade without clear.

Rattle-can stuff probably needs it too - not sure - once you shoot automotive paint, you'll not use RC paint again.

I use cheap rattle can. Paint usually gets damaged or need to rebuild rocket long before I would need to re-finish it. I fly a lot of LOC parts rockets and need to replace the tubes every 15-20 flights. Lost, cato, recovery failure, there are plenty of ways you need a rebuild. I have some that haven't earned their paint yet

 

[tomsteve]

My issue has been trying to get all and I mean ALL the low spots sanded. Since the paint was rustoleum white gloss, the low spots are very visible and glossy

I’ve had issues sanding to close to the primer coats that you can see the shade of gray

From my knowledge, enamel should be spray more than three coats do to it being prone to runs

Noted

i dont think amount of coats sprayed causes runs. too heavy of a coat does.
if you are using spray bombs, they are thinned down quite a bit to spray at a low pressure so each coat is pretty thin.
i suggest spray 3-4 more coats and sanding again.

 

[Hobie1dog]

if you are using spray bombs, they are thinned down quite a bit to spray at a low pressure so each coat is pretty thin.i suggest spray 3-4 more coats and sanding again.

+1, they are just a convenience, so yes the quality is sometimes pathetic. Low Solids, very cheap nozzle