Paint Problems?

[captain26]

Since delclaring myself a BAR and building several rockets since renewing my love of rocketry, I've strived for better finishs on models. The rockets I built as a young boy were built to fly, not be pretty! My problem since returning is paint finish. I've been using rattle can Krylon for all my rockets, primer and finish coat. In the last couple of weeks I've gotten a can of primer that was cloudy water at best and a can of gloss banner red that was glossy, satin, flat and some other unGodly coat all in one spraying! I'm not a bad painter, I know good technique and spray in multiple light coats, not heavy runny disasters. I've seen many great looking models in the project forums, what's your secrets? Are there better rattle can paints available or is it necessary to have an air brush for stunning finishes? I really don't want to invest in expensive guns/accessories. Thanks for any advice!

[chrism]

Look through Leo's and Scigs30 build threads for their methods on finishing. These two guys give their rockects fantastic finishes.

[stefanj]

Is it very humid where you are?

High humidity can cloud otherwise glossy finishes.

The cure is to wait for the paint to THOROUGHLY dry (I don't know how long for the new Krylon) and then use polishing compound. You don't know glossy until you've compounded and buffed your paint job.

[Gary Byrum]

Krylon has issues with humidity. I get satin finishes at best on humid days. With Krylon in mind, their clear coat can blister their own paint. I am going to attempt using Future floor finish as a gloss finish. Application can easily be found if you Google it. Regarding their primer, it stinks. I've heard of folks using KILLS but this too has issues with the glassine covered tubes. I hear that the Krylon gray primer is a better alternative and use a white or preferred base color on top of that. I, like you, am still working on these same issues.

[captain26]

Well, if humidity can be a factor, I'm out of luck right now! I live about 30 miles south of Atlanta, GA - this time of year, the air is THICK! :eek: I'll have to give the rubbing compound a try, sounds promising. Here lately, to cover up the blotchy paint jobs, I just shoot the model with flat after applying decals. Seems to hide most of the problem but would like a nice glossy model occasionally!

[Scott6060842]

As far as my rattle can experiences go....

I really like the Rustoleum 2X coverage line sold by Home Depot. I have not had good results with Krylon.

[mycrofte]

Same here. I went back to the cheapo stuff after problems with the new Krylon.

[DaveR]

Valspar from Lowe's is a good rattle can paint.

[captain26]

Thanks for the tips guys! I'm going to try a different brand of rattle paint and check my results. We're having a club launch this coming Saturday and was hoping to have my nice and shiny Super Big Bertha in 1970 paint scheme ready for action but looks like she'll be sporting a flat finish to cover the assorted finishes! Best to all

[luke strawwalker]

Yes, as previously mentioned just about ANYTHING is better than the "new" Krylon. Conditions have to be pretty much perfect and you better be an ace painter to get even decent results out of this stuff... the worst thing IMHO is that it doesn't even like to play nice with Krylon primers and even previous coats, even when religiously following recoat times!

Sorry but I'm not paying good money for crappy paint!

As mentioned, Valspar is a good brand, as is Duplicolor. Rustoleum is okay as well. I've had MUCH better luck with Walmart Colorplace 99 cent a can stuff than the new Krylon, but the colors are very limited and the red primer is no more and the gray primer's getting hard to find, so I'll probably have to switch primers when I run low...

You'll have to experiment a bit and see what works best for you...

Good luck! Later! OL JR :)

[jetlag]

Duplicolor lacquers, available at auto supply houses, has fantastic high-build up primers and beautiful colors. A little pricey, but well worth it if you want a professional finish. All the above will be useless if you do not fill the grain on the wood (or use paper labels as some here do). Filling spirals on the body tubes is also good if you like going that far. I do for sure.

Apply decals and clear over with Future (now called Pledge) once they are dry. So glossy, you will need sun glasses!

Allen

[LeeR]

Yes, as previously mentioned just about ANYTHING is better than the "new" Krylon. Conditions have to be pretty much perfect and you better be an ace painter to get even decent results out of this stuff... the worst thing IMHO is that it doesn't even like to play nice with Krylon primers and even previous coats, even when religiously following recoat times!

Sorry but I'm not paying good money for crappy paint!

As mentioned, Valspar is a good brand, as is Duplicolor. Rustoleum is okay as well. I've had MUCH better luck with Walmart Colorplace 99 cent a can stuff than the new Krylon, but the colors are very limited and the red primer is no more and the gray primer's getting hard to find, so I'll probably have to switch primers when I run low...

You'll have to experiment a bit and see what works best for you...

Good luck! Later! OL JR :)

For everyone living with humidity, I sure appreciate your frustration. On the extremely rare day that we have humidity, I do not paint.

Being a big fan of the old Krylon, I was concerned with comments about the new formulation when it came out. But I've found I can get incredible finishes with it, however, it does take a little bit of time to get used to it. I am sure that the biggest factor for me is the dry climate in Colorado. I follow the instructions of doing multiple light coats a few minutes apart, with my last coat being a little heavier, to get a good, wet finish. I then usually let it dry for several days before handling.

Also, by far, the best primers I've found are Plastikote, and Duplicolor. Both build well, and dry fast, and sand easily. I had to go to the Plastikote website to find dealers, since it seems like fewer places carry it now. And I used to find Duplicolor at Walmart, and now I think I'd have to go to an auto parts store. I hated the old formula Krylon primer, and really feel no reason to try the new formula, since Plastikote and Duplicolor work so well.

As far as other paints, I really like Rustoleum Lacquer, but you have to love red, black, and white. But I have found it compatible with the Testors and Model Masters lacquers. I used to get the Rustoleum Lacquer at Hobby Lobby, but our local stores stopped carrying it. I guess it is time to go back to the web to see where it is being sold.

UPDATE: I was just at Home Depot, and they carry the Rustoleum Lacquers.

[jharding58]

ibid LeeR

Also I have this document from who knows when.

[LeeR]

That is a pretty good overview of the different paint formulations. Thanks for posting.

[Doug Sams]

Since delclaring myself a BAR and building several rockets since renewing my love of rocketry, I've strived for better finishs on models. The rockets I built as a young boy were built to fly, not be pretty! My problem since returning is paint finish. I've been using rattle can Krylon for all my rockets, primer and finish coat. In the last couple of weeks I've gotten a can of primer that was cloudy water at best and a can of gloss banner red that was glossy, satin, flat and some other unGodly coat all in one spraying! I'm not a bad painter, I know good technique and spray in multiple light coats, not heavy runny disasters. I've seen many great looking models in the project forums, what's your secrets? Are there better rattle can paints available or is it necessary to have an air brush for stunning finishes? I really don't want to invest in expensive guns/accessories. Thanks for any advice!As mentioned, you're getting blushing. As the solvent molecules in the paint evaporate, they absorb heat thereby cooling the air around them. (Recall "heat of vaporization" from chemistry or physics.) If the dew point is high - ie, if it's a hot, humid, summer day - the rapidly cooling air will cause the humidity therein to condense...in your paint :( This is what causes the dull finish.

Paints with hot solvents - ie, "lacquers" - tend to do this the worst. This includes many "fast drying enamels" such as the old Krylon. (It's really more of a lacquer.) Other paints, such as Duplicolor, Plastikote and old RustOleum Painter's Touch will all be more prone to blushing. Some of these are labeled as lacquers while the others are called enamels, but if they use the hotter "fast drying" solvents, they're gonna be more prone to blushing.

I've had great luck with the RustOleum premium line ("Stops Rust") here in north Texas. It stands up well (except for the black; don't know why). I've used Valspar black with good success here.

The RustOleum premium is much slower drying. But if you can wait overnight, you'll get a very satisfying result. In my case, I bring them in the house after applying the final coat, and they're dry to the touch by morning.

Here's a shot of some RustOleum red that I was very pleased with. (No clear topcoat was applied.)
http://www.doug79.com/apogeedx/fairing-p.jpg

Doug

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[Earl]

Well, if humidity can be a factor, I'm out of luck right now! I live about 30 miles south of Atlanta, GA - this time of year, the air is THICK! :eek: I'll have to give the rubbing compound a try, sounds promising. Here lately, to cover up the blotchy paint jobs, I just shoot the model with flat after applying decals. Seems to hide most of the problem but would like a nice glossy model occasionally!

Yep, I'm over in Augusta (but lived my first 8 years of life in the Morrow/Forest Park area) and this time of year is about hopeless as far as gloss paint application goes. Humidity is just awful.

You can do primer coats and flats, but that's probably gonna be about it. I've got several models in the build que that are primered out and sanded and ready for final finish coats, but that's gonna be October weather work.....and late October at that unfortunately.

In these type climates an indoor paint booth would be the ticket for sure and one day I'm gonna set one up.

Earl

[captain26]

You're right Earl, lately it's like living in a sauna! Applied decals last night to the SBB, hope to get the flat on later today (between thunderstorms!).

Again, thanks to all for the great advice and paint tips! I have several auto stores and Home Depot/Lowes near where I live so I'll check out some of the suggested paint products. I've got a SEMROC Defender close to final paint and now plan on using one of the suggested formulas. Being all white with some black details, should be able to find the right colors. I'll post pics and results when completed.

[sandman]

Currently here in Michigan it's freakin' miserable out! :mad:

High of 99 degrees today with the humidity well over 90%.

My concrete floor being cooler is actually damp!

OK, my dogs love that part! ;)

I worked out in my "un-airconditioned" shop yesterday and had to change my soaking wet shirt 3 times!

NO PAINTING today!

The only good thing was using Gorilla glue. It cures with moisture and I didn't need to use any water to wet one part to be glued.

I just wiped it on my forehead (yea, gross).

The blushing in the paint on high humidity days is from the relative rapid cooling of the spray paint.

The paint in the can is the same temperature as the outside air but, when it sprays out it rapidly expands which means that the same amount of heat in the paint is now occupying a much larger volume. That's basically how an air conditioner/refrigerator works.

You can experience this with spray on deodorant. It's always cold when the spray hits your pits. Exactly the same thing!

The abrupt drop in temperature causes the high humidity in the surrounding air to condense.

The condensed moisture on the paint surface is what causes the blushing.

Most light colors get a flat finish from this blushing but dark colors really get crappy! Cloudy, rainbow effect...not pretty!

The only cure is to refinish on a dryer day.

[jetlag]

All of the above humidity complaints are why I prefer to paint in air conditioning. Here in Columbia, the heat index today will be around 115F with an air temp of 103F. If I waited until conditions were right, I'd have to wait until Fall/Winter to get any painting done.
You folks need to go to the Wally Fart and buy an air conditioner for your shop. You'll be glad you did. :D
Gordy, I can't believe you have not done that already!

Allen

[Doug Sams]

You folks need to go to the Wally Fart and buy an air conditioner for your shop. You'll be glad you did. :D I have one, Allen. But I can't get a good seal on my door so it rapidly warms up when I turn it off. And I don't want to leave it running while I'm spraying - I don't want all that overspray circulating into the filters and clogging them up.

I've studied what it takes to seal the door, but I think the real problem is that the driveway is crowned in the middle which causes gaps at either end of the door-to-ground junction. So it's not so simple as adding a new rubber to the bottom of the door :(

But the AC's good for working in the garage. It at least makes it bearable.

Doug

.

[sandman]

All of the above humidity complaints are why I prefer to paint in air conditioning. Here in Columbia, the heat index today will be around 115F with an air temp of 103F. If I waited until conditions were right, I'd have to wait until Fall/Winter to get any painting done.
You folks need to go to the Wally Fart and buy an air conditioner for your shop. You'll be glad you did. :D
Gordy, I can't believe you have not done that already!

Allen

My shop is a pole barn.

Not real easy to add efficient A/C.

I just work and sweat. :rolleyes:

[jetlag]

Well, Gordy, you need to make you a paint booth/room in the barn and A/C it. I know, a lot easier said than done, right? But with your considerable talents, you should be able to make it happen! :D
What's a pole barn---or---is it different than a standard barn?

Allen

[sandman]

Well, Gordy, you need to make you a paint booth/room in the barn and A/C it. I know, a lot easier said than done, right? But with your considerable talents, you should be able to make it happen! :D
What's a pole barn---or---is it different than a standard barn?

Allen

A "Pole Barn" refers to the way the building is built.

Instead of a foundation and 2 x 4 walls a pole barn it based on a bunch of pressure treated poles (6" x 6" and 6" x 8") set in bored holes in the ground and filled with cement set on 8 foot center then linked with 2 x 4's run horizontally between the pole.

Trusses are placed on top for the roof, siding is nailed to the sides and a poured concrete floor.

Pretty cheap construction really and you get a lot of space for a relatively cheap outlay of cash.

Mine was a kit I purchased in 1985.

[jharding58]

My shop is a pole barn.

Not real easy to add efficient A/C.

I just work and sweat. :rolleyes:

The sweat adds to the durability of machined balsa pieces - not to mention the aromatic nature of freshly delivered cones.

[Gary Byrum]

@ Sandman...That pretty groovy man. Unfortunately for some of us, we have our shops inside our homes where no painting can be done. Too bad I don't own this property or I'd have an out building / shop here. I already have the spare AC.

[luke strawwalker]

Currently here in Michigan it's freakin' miserable out! :mad:

High of 99 degrees today with the humidity well over 90%.

My concrete floor being cooler is actually damp!

OK, my dogs love that part! ;)

I worked out in my "un-airconditioned" shop yesterday and had to change my soaking wet shirt 3 times!

NO PAINTING today!

The only good thing was using Gorilla glue. It cures with moisture and I didn't need to use any water to wet one part to be glued.

I just wiped it on my forehead (yea, gross).

The blushing in the paint on high humidity days is from the relative rapid cooling of the spray paint.

The paint in the can is the same temperature as the outside air but, when it sprays out it rapidly expands which means that the same amount of heat in the paint is now occupying a much larger volume. That's basically how an air conditioner/refrigerator works.

You can experience this with spray on deodorant. It's always cold when the spray hits your pits. Exactly the same thing!

The abrupt drop in temperature causes the high humidity in the surrounding air to condense.

The condensed moisture on the paint surface is what causes the blushing.

Most light colors get a flat finish from this blushing but dark colors really get crappy! Cloudy, rainbow effect...not pretty!

The only cure is to refinish on a dryer day.

Interesting description...

If this is true, then raising the latent heat of the paint would help or even eliminate the problem--

Put the paint can into hot water for a few minutes to increase the heat of the paint inside it. That way, when it's sprayed out of the can and expands, it cools, but not below the dew point of the outside air, eliminating the condensation problem. Bringing cans from a cooler/colder environment into the hot humid outside air would exacerbate the problem, having exactly the opposite effect of heating the can.

Additionally, heating the can somewhat would raise the propellant vapor pressure and should result in a finer spray droplet size and wider pattern, and have a slight effect at reducing the viscosity of the paint.

I know it really helps to dunk a can of freon in hot water before/while putting it into a car AC system... the hot freon boils off easier and has a higher vapor pressure in the can, forcing it into the AC system faster. (Freon cans will completely frost over to the liquid level sometimes when putting it into an empty AC system). I typically set the can on either a heater hose, radiator hose, or the manifold to thoroughly heat the can and force as much freon out into the system as I possibly can before disconnecting it as well...

Interesting ideas! OL JR :)