Finishing Questions

[BatPlane]

New guy here. Here are a few questions for you veteran builders / chemists:

1. Butyrate Dope products like the AeroGloss brand sanding sealer and/or color dope can be used on wood and UNDER pretty much any kind of paint. Enamel, lacquer, or acrylic can be used OVER AeroGloss Butyrate products, correct?

2. Correct me if I'm wrong but enamel or acrylic can go OVER lacquer, just not vice-versa, right?

3. Would these would be compatible, acceptable finishing methods?
a. Butyrate sanding sealer, Testors Enamel color, Testors Enamel clear coat
b. Butyrate sanding sealer, Testors Lacquer color, Testors Lacquer clear coat
c. Lacquer primer, Enamel color, enamel clear
d. Enamel primer, enamel color, enamel clear

4. Butyrate over enamel or lacquer primer would be a disaster, lacquer over enamel would be a disaster also, correct?

If I got any of this wrong, please tell me! I'm trying to learn what I'm doing.

[sandman]

Everything you have there is correct except....

The clear...

Test it first!!!!!

Also, if you are doing a two tone paint job make sure the second color is the same brand and type of paint...but even that is no guarantee.

A lot of us "experts" at finishing have and still do screw up a perfectly good finish with the wrong clear coat!

But not me...I've NEVER done that. :rolleyes:

[Doug Sams]

3. Would these would be compatible, acceptable finishing methods?
a. Butyrate sanding sealer, Testors Enamel color, Testors Enamel clear coat
b. Butyrate sanding sealer, Testors Lacquer color, Testors Lacquer clear coat
c. Lacquer primer, Enamel color, enamel clearYes.


d. Enamel primer, enamel color, enamel clearIf the primer is allowed to dry long enough, you should be OK. Personally, I avoid the enamel primers because they're really not primers - they're flat paints and as such need to be treated the same as paint when top-coating.


4. Butyrate over enamel or lacquer primer would be a disaster, lacquer over enamel would be a disaster also, correct?In all likelihood, these would be problematic.


Enamel color, enamel clearIMO, putting a clear coat on an enamel shouldn't be necessary. Unless the enamel was dull - perhaps due to blushing or because it's satin or flat - the clear coat doesn't add much. An enamel paint is called enamel because of its hard, durable finish. The underlying concept is that it goes on without need for followup finish (as opposed to lacquer which must be buffed and/or clear-coated).

That's why I like Rust-Oleum and Boyd's so much. Put 'em on and I'm done. No futzing with clears and waxes. And they're not prone to blushing like so many of the fast drying enamels such as Krylon, Testors, Painter's Choice, et al.


Doug

[Doug Sams]

Test it first!!!!!

Also, if you are doing a two tone paint job make sure the second color is the same brand and type of paint...but even that is no guarantee.

A lot of us "experts" at finishing have and still do screw up a perfectly good finish (snip)Yes, I wholeheartedly agree, $tuff happens. No matter how careful one is, sometimes a finish job still goes awry.

Doug

[Solomoriah]

Gah, no kidding. Primed my Thunderbee, painted it two tones, and clearcoated... bubbles. Sanded off, primed, painted, clearcoated with a different clearcoat... more bubbles. Sanded off, primed, painted, and used Future. No bubbles.

I like clearcoat spraypaint better than Future, but sometimes you just do what you have to do.

[Doug Sams]

That's why I like Rust-Oleum and Boyd's so much. I should add...These slower drying enamels use weaker solvents that are much less likely to have bad reactions with the underlying coats. For example, sometimes I will simply sand a finish coat down (with 320 or 400) and then apply a new finish coat without first using a primer.

With these "cooler" enamels, there's little fear of the underlying coats crazing. OTOH, since good primers are inherently hotter, using one over the sanded coat could well cause problems.

On some birds, I paint the entire rocket one color, maybe fly it once or twice, then later add the complementary colors such as a red fin on a yellow rocket. Once the yellow is sanded, the red will bond perfectly fine without need of a primer.


Doug

[BatPlane]

Personally, I avoid the enamel primers because they're really not primers - they're flat paints and as such need to be treated the same as paint when top-coating.

IMO, putting a clear coat on an enamel shouldn't be necessary.
Doug


You know, I've used Testors Flat Gray Enamel primer and came to that conclusion! it appears that it's just a flat "primer colored" enamel paint!

And....yeah, I've had the same experience with the enamel clear coat. It's probably not necessary. (One thing I did learn, though....if you get a fingerprint on the model before the paint dries, a coat of clearcoat completely obliterates it!)

[BatPlane]

Son of a &**&^^^!!!!!!

I forgot one tidbit to put in the initial post.....

What the heck kind of product is Krylon Primer? Lacquer??? It dries really fast and seems like just about anything can go over it OK....

It's gotta be! Let me know, guys.

Thanks for the input, keep it comin'.

[ghrocketman]

Wholeheartedly agree that enamel primers are horrible.
Most of them are "primer" colored flat paints that are not designed as a "sandable" primer.
I'm pretty sure that Krylon primer is "lacquer-based" and is similar to Automotive primers.
Lacquer can be topcoated with enamel, but you cannot put Lacquer over anything but Lacquer or Dope.

[Solomoriah]

Not sure what it actually is chemically, but Dollar General sells "Miracal" primer in gray and red oxide colors, and it absolutely is sandable. I have excellent luck with it, and at $1.00 per can the price is unbeatable.

[pantherjon]

Not sure what it actually is chemically, but Dollar General sells "Miracal" primer in gray and red oxide colors, and it absolutely is sandable. I have excellent luck with it, and at $1.00 per can the price is unbeatable.


That's all I use for primering now too(the Miracal)...I did pick up a can of Krylon primer a few weeks ago at our local Lowes and tried it..Yuck..Will stick with what works, and at $1.00 a can it sure beats the Krylon which was $2.99 :)

[BatPlane]

Just out of curiosity, what didn't you like about the Krylon primer? The stuff definitely stinks, that's for sure. But it does seem to dry quickly, it fills in the grain in wood and is sandable. It also seems compatible with everything.


I was just wondering since I've got a bunch of cans around anyway. Thanks.

[Solomoriah]

Just for the record, I've never used the Krylon primer. I've used Kilz, but I didn't find it to be as good for me as others had said it was for them. Miracal does what I want, so that's what I use.

[pantherjon]

Just out of curiosity, what didn't you like about the Krylon primer? The stuff definitely stinks, that's for sure. But it does seem to dry quickly, it fills in the grain in wood and is sandable. It also seems compatible with everything.


I was just wondering since I've got a bunch of cans around anyway. Thanks.

Didn't seem to go on well..Kept spraying and spraying and no coverage..Maybe I got a bum can with mostly propellant, but for now am going to stick with the Miracal that I can get for $1/can as opposed to Krylon at $3/can..

[BatPlane]

Didn't seem to go on well..Kept spraying and spraying and no coverage..Maybe I got a bum can with mostly propellant, but for now am going to stick with the Miracal that I can get for $1/can as opposed to Krylon at $3/can..

You got a bad can, definitely. Every time I've used it, it covered everything thoroughly & quickly.

I am switching to AeroGloss Sanding Sealer anyway because I like the hard smooth surface it provides. I'm sure it adds some strength to the balsa fins, too and is a harder surface for the paint to go over.

Hey, if the Miracal works stick with it....was just wondering what the prob. with the Krylon was...

[ScaleNut]

krylon no longer sells a true "sandable" primer , the last cans I saw were about 2 years ago (with the colored balls on the label) .and it was good stuff !
they still make a "primer"( grey,black,white colored balls on the label) but it is more like paint than what I would call primer .

"sandable" primer is more of an automotive thing and great for filling, krylon is not really catering to that realm of products.

it's a shame because I really liked their sandable primer.

they may sell a sandable primer in one of their specialty lines that I am not aware of

[Solomoriah]

Miracal primer is sandable, because (my theory) the average buyer is painting a car the cheap way. It's a Dollar General thing...

[stantonjtroy]

I'll chime in because finishes are what I do for a living. I almost exclusively use Dupont 2510S primer/sealer or Awl Kwik 545White. Both are epoxy based paints. I won't lie, they're not cheap but they are available in quart kits and that will do a fair number of rockets. As they are a 2part mix, shelf life isn't bad either. 2510S is available anyware you can get auto paint (ex. Carquest) and 545 can be purchased at any of the better marine supply shops (ex. West Marine). A quart of either w/ converter runs around $50. Closer to the hobby line, K&B used to make an epoxy based primer. 1 to 1 pint cans if memory serves. Not sure of a retailer but here's their link: http://www.mecoa.com/acc/paint/index.htm . In any event, all three are sandable, fill minor surface defects like grain and spirals and as long as they are preped with a 300-400 grit paper, all will take any topcoat. I useally use a urithane topcoat for mid and high power and rustoleum for LPR. FWIW.

[Maniac BAR]

Anyone tried the Wally world gray primer? At $1 a can I have been using it on my rockets with out any problems. The biggest thing with primers is drying time. The heavier the coats, the longer you need to let it set up. If you needed that heavy a coat to begin with, an automotive sanding/sealer would have been better.
I have used the Krylon primer but have not liked the sanding properties. The first few passes with sandpaper really clogged up the paper. At least using it dry. Plus, it takes up to a week for it to finally do dry. The Walmart primer can be sanded the next day and does so very easily.
When I prime I do the first two or three coats very thin. You can almost see through it. The last coat goes on fairly heavy so that it looks wet. Don't worry about fuzz or dirt or a rough texture as most of the primer is sanded off.
Once sanded and primed with no more flaws visable, I give it a quick smooth last coat. A quick dusting with 400 when dry and it is ready for paint.
This has worked for me.

[Solomoriah]

I think the Wal-Mart ColorPlace primer and the Dollar General Miracal primer are exactly the same thing. Probably from the same factory.

[Maniac BAR]

I think the Wal-Mart ColorPlace primer and the Dollar General Miracal primer are exactly the same thing. Probably from the same factory.

Wouldn't surprise me at all. I just know the stuff works for me and you can't beat the price. Some of my larger rockets can use up two or three cans. Still cheeper than the automotive stuff and generally easier to use. :p
If you are using rattle cans to paint you should pick up one of those trigger things. They snap onto the top of the rattle can and you pull a trigger which pushes down on the spray nozzle. Really makes the whole process easier and less painful on your finger. :)

[Solomoriah]

If you are using rattle cans to paint you should pick up one of those trigger things. They snap onto the top of the rattle can and you pull a trigger which pushes down on the spray nozzle. Really makes the whole process easier and less painful on your finger. :)
Wouldn't be without mine. I have two.

[CPMcGraw]

Solo and ManicBAR,

Do you guys have a Harbor Freight nearby? My "new favorite" tool for this job is a pair of detail spray guns (item #92162) that I picked up for about $9 each (or less, on sale). They come with a 4 oz paint cup, which gives me enough primer (Kilz thinned with clean mineral spirits about 80-20 or 75-25) to single-coat about six models in a batch.

I like the way Kilz sands, but not the way the spray cans deliver it. Too much trapped gas in the mix -- looks like the surface of the moon when it dries. Using the spray gun, however, there is no trapped gas. The primer goes on in a much thinner layer that dries better.

Granted, you'd still need an air compressor...

[Solomoriah]

I have a pretty nice compressor, actually. I hate cleaning nozzles though.

No Harbor Freight anywhere in 100 miles of here anyway.

[moonzero2]

Anyone tried the Wally world gray primer? At $1 a can I have been using it on my rockets with out any problems. The biggest thing with primers is drying time. The heavier the coats, the longer you need to let it set up. If you needed that heavy a coat to begin with, an automotive sanding/sealer would have been better.
I have used the Krylon primer but have not liked the sanding properties. The first few passes with sandpaper really clogged up the paper. At least using it dry. Plus, it takes up to a week for it to finally do dry. The Walmart primer can be sanded the next day and does so very easily.
When I prime I do the first two or three coats very thin. You can almost see through it. The last coat goes on fairly heavy so that it looks wet. Don't worry about fuzz or dirt or a rough texture as most of the primer is sanded off.
Once sanded and primed with no more flaws visable, I give it a quick smooth last coat. A quick dusting with 400 when dry and it is ready for paint.
This has worked for me.

Good to know,... then is Krylon paint OK to use on top of this primer?

[Maniac BAR]

The Krylon paint is excellent on top of the Walmart primer. It is almost all I use. I have used Plasticoat and Duplicolor as well with no problems at all as far a compatability is concerned. :p

As for the auto paint sprayer, I have four guns. One is just for primer and the others are for different paints. Plus two different smaller touch up guns. Yes, I used to do that for a living. I now have my limit of chemicals in my system and was told to stop doing it. The occasional rocket paint job doesn't add any more to my system since I paint outdoors. However, it is really a lot of work to mix, spray and then clean up the equiptment. Unless it is a large (10') rocket I can do just as nice a job with the rattle cans. That trigger attachment makes it very easy. ;)

As far as Harbor Freight, there is one about 10 miles from my place unfortunately! :rolleyes: I try to stay away. I don't really have any more room in my garage for more stuff. As far as their equipment is concerned, I would proceed with caution. Some of the stuff is good, some is not great. The concern I would have with their paint spray guns is whether it drips or not. Some of the cheeper guns do not seal well at the cup lip and when tilted at an angle, they will drip paint onto your work. :mad: Also, how much oil or water will their compressors accumulate in the air tank as they run. Good compressors have better internal seals to limit the amount of that junk.

The compressor is another thing. However, Sears has a really nice one on sale here right now that is small and hangs on the wall!!! :) Just remember they tend to be very noisy and if you are using large spray guns you need a good size one plus a quality regulator and water filter. For that amount of money you could buy a boodlewad of rattle cans!!!! :p

[handeman]

For that amount of money you could buy a boodlewad of rattle cans!!!!

Yes you could, but you can't pump up your car tires!

I can't beleive I'm torturing myself reading this thread. I waiting for the last coat of paint to dry too. I'm painting the family room! :( The wife desided she wanted it done this weekend. No problem with that, it needed doing. Her schedule had it done yesterday. Now I'm in the dog house because she had an over optimistic idea of how long it takes to prep, and paint a room that need some drywall work and mud.

Enjoy painting the rockets!

[Maniac BAR]

OUCH!!!!! I get a headache everytime I check the honeydo list!!!!

[Tau Zero]

krylon no longer sells a true "sandable" primer , the last cans I saw were about 2 years ago (with the colored balls on the label) and it was good stuff !

They still make a "primer"( grey,black,white colored balls on the label) but it is more like paint than what I would call primer.I think the Wal-Mart ColorPlace primer and the Dollar General Miracal primer are exactly the same thing. Probably from the same factory.I used a can of the "gray ball" Krylon primer last week, and it's *nothing* like the "colored ball" Krylon primer I used to use. ScaleNut's right when he says the "new" Krylon primer is basically just very thin flat paint. :mad:

I'll have to make a pilgrimage to Wally-World tomorrow to see if I can rustle up some of the "ColorPlace" primer. :eek:


Cheers,