stunthanger.com
Building Tips and technical articles. => Paint and finishing => Topic started by: Andrew Borgogna on May 06, 2013, 10:32:44 AM
-
I have been using Painter Touch paint from Rust-Oleum for some time now with great results, until last week. I laid down a coat of yellow and the next day I wet sanded the paint and applied a coat of gloss clear. The yellow began to wrinkle, it had to be sanded and repainted. I sent a email to Rust-Oleum explaining what happened and below it their response.
Thank you for contacting Rust-Oleum Product Support.
Aerosol paints will dry by oxidation. A skin forms on the surface, and then gets thicker as the solvent evaporates from the paint below the skin until eventually it is fully cured all the way through the coating. If you recoat the paint before it has skinned over and begun to dry to the touch, the two paints dry like a single coat of paint. This skin-free time varies from paint to paint, but is usually about an hour or so at room temperature.
After the skin has started to form, it is very fragile and if recoated at the wrong time it may wrinkle, blister or crack. Always refer to the can instructions for the proper recoat time, as this may vary from product to product. Most of our paints can be top coated or recoated either within one hour or after 48 hours. This means that you can topcoat within the first hour, while the previous coat is still tacky, however if the last coat has been drying for longer than an hour, you must then wait a full 48 hours before the next coat can be applied. Cooler temperatures, higher humidity, or a heavy application can extend these recoat times.
In short, wait 15 minutes and repaint or wait 48 hours, but not overnight.
Andy
-
Yup.
Their "Aerosol paints will dry by oxidation" is a bit incorrect. Oil based enamel paints (like Rustoleum) will continue to cure by oxidization after the solvent has dried out of it (this is why folks tell you to wait two weeks before splashing fuel on your Rustoleum-painted model), but I don't think oxidization plays much of a role in lacquer-based finishes (i.e. Krylon).
(and two-part paints like epoxies cure by an entirely chemical process after the thinner (reducer, whatever) has flashed off -- the thinner is only there to give the stuff the right consistency for brushing or spraying).
Now Mark Scarborough can jump in and tell you where I'm wrong...
-
Yup.
Their "Aerosol paints will dry by oxidation" is a bit incorrect. Oil based enamel paints (like Rustoleum) will continue to cure by oxidization after the solvent has dried out of it (this is why folks tell you to wait two weeks before splashing fuel on your Rustoleum-painted model), but I don't think oxidization plays much of a role in lacquer-based finishes (i.e. Krylon).
(and two-part paints like epoxies cure by an entirely chemical process after the thinner (reducer, whatever) has flashed off -- the thinner is only there to give the stuff the right consistency for brushing or spraying).
Now Mark Scarborough can jump in and tell you where I'm wrong...
well Tim,, sorry,, but yeah
quoted
Oxidation: Chemical reaction upon exposure to oxygen. Some coatings cure by oxidation, when oxygen enters the liquid coating and cross-links the resin molecules. This film-forming method is also called "Air Cure" and "Air Dry." (Oxidation also causes rust on bare metals.)
so, oxidation is in fact a valid statement,, depending upon the chemical composition of the paint,, it does "oxidize" in order to crosslink,, I believe this is how aerosol "epoxy" type paints cure,,
but to the point of this thread,, recoat sensitivity is a very critical component of paint application, lacquers typically dont have any issue with it, except for some cab lacquers which have a crosslinking component in the resin.
However, enamels, and virtually every other type of paint will have some recoat sensitivity,, when you violate it, it gets ugly,,
-
Their "Aerosol paints will dry by oxidation" is a bit incorrect. Oil based enamel paints (like Rustoleum) will continue to cure by oxidization after the solvent has dried out of it (this is why folks tell you to wait two weeks before splashing fuel on your Rustoleum-painted model), but I don't think oxidization plays much of a role in lacquer-based finishes (i.e. Krylon).
(i.e. Krylon) Is not lacquer its enamel
It's no wonder you are having trouble. To begin with, Krylon is no
longer the Krylon you're used to. This is due to the EPA meddling in
the product. I spent the last two weeks wasting money and trying to
solve a wrinkling/lifting problem (very similar to your reptile skin
appearance), including at least seven calls to Krylon. Desperation was
setting in since I was modifying a large model I built two years ago
for a land developer. Used Krylon at that time and had no problem and
went into this project using exactly the same Krylon paint so that
everything would be compatible. I thought. Boy, was I wrong!
Without making this story way too long, here it is in a nutshell. Up
until a year ago, the Krylon that we've all been used to was an
acrylic lacquer. Dries in 12 minutes and can be recoated without any
worry relative to the previous coat reacting. Unfortunately, the EPA
in their wisdom came up with regulations that resulted in Krylon
reformulating their old, reliable acrylic lacquer into an oil-based
enamel. Not just an ordinary enamel but an oil-based enamel. This has
several very interesting and very bad results where the modelbuilder
is concerned.
You now have a window of application, followed by an extended drying
period before it can be resprayed. The instructions on the back of
the can are very specific and MUST be followed to the letter. To begin
with, spray a light coat, wait five minutes and spray another light
coat. Repeat the process until you have the desired coverage. Keep in
mind that all spraying MUST be completed within one hour or the
underlying coats will wrinkle and lift. Not MAY but WILL. After that
one hour time period, you MUST wait a minimum of 24 hours before
applying another color coat or the previous coats that you thought
were dry will...you guessed it....wrinkle and lift. Do be aware that
24 hours in the MINIMUM waiting period. Depending on how many previous
coats you applied in the one hour time frame, you may have to wait
more than 24 hours to apply additional coats.
Although the instructions don't indicate the need for a base coat,
this stuff is so weird that I would definitely recommend a primer
base. However, even the primer is an oil-based enamel with the same
window of application and drying time. Be that as it may, be sure to
used the Krylon primer so that everything is compatible.
Finally, because you're dealing with an oil-based enamel, plan on an
extended painting session and multiple coats in order to prevent runs.
Because it doesn't have the 'tooth' or grab of acrylic lacquer,
applying enough paint to attain an opaque coat...especially where
white is concerned... white is concerned...<wbr>is guaranteed to result in
Oh, one last comment. According to Krylon, changing the formula from
an acrylic lacquer to an oil-based enamel made the product more user
friendly for the average consumer. I don't know about the average
consumer, but it did just the opposite where the modelbuilder is
concerned.
By the way, if you're still longing for the old Krylon acrylic
lacquer, it can still be found. As an industrial paint. Order it from
industrial suppliers in six-can quantities and use it over Dupi-Color
Gray Primer and Filler that, as far as I know, can only be found in
NAPA Auto Supply stores.
Don't get the idea that you can find another brand of spray paint that
will do the same job with a shorter wait time. ALL of them have
suffered at the hands of the EPA. The window of application ranges
from one to four hours and the wait time to recoat can be as long as
two to seven DAYS. You can also forget picking up pure lacquer
automotive paint that used to made by DuPont and available from
automotive paint stores. DuPont doesn't make it any more. Thank the
EPA for that as well.
Hope some of this helps.
"Richard Marmo, IPMS/USA #2
The Modeler's Weapons Shop
Scale Publications
Modelbuilding Services by Richard Marmo"
-
Many years ago, there was an article in one of the model magazines.
This modeler painted his models, sprayed them actually, with: "Industrial" grade Rust-o-leum enamel.
Sold only in cans. Said the stuff, after curring a but, was fuel resistant and fuel proof.
Had nice models. Couple of large R/C biplanes were featured in the article.
Possibly someone may remember it?
Charles
-
>>Oxidation also causes rust on bare metals<<
Not to be picky, but only iron rusts. Other metals oxidize (I know, rust IS oxidation but it's a semantics thing). Brass, aluminum, copper all will oxidize, too. Copper develops verdigris (oxidation). Brass, patina (also oxidation). I think only aluminum gets oxidase.
;D
-
wanted to confirm it so I sent an email to Krylon. Official answer:
.... Due to Federal VOC restrictions on solvent based paints, we were forced to change the formula from a lacquer to an alkyd. Lacquers can be recoated anytime, whereas alkyds need to be recoated within one hour or after 24 hours. Once the alkyd resin starts curing, if a new coat is applied over it, wrinkling will likely occur.
The old version is still available through our "Industrial" distribution as such products are not as regulated as "Consumer" paints are - which is our line. However, it will not have the new spray nozzle etc. You can find these products at such suppliers as Grainger or Fastenal.
http://www.grainger.com/Grainger/wwg/search.shtml?op=search&searchQuery=krylon+Krylon&Ntt=krylon+Krylon&sst
=All&L2=Paints&operator=mfgRefinementSearch&originalValue=krylon&L1=Krylon
http://www.fastenal.com/web/products...tial&N=0&Nty=1
It is NOT fuel proof, fuel resistant is is not fuel anything so use at your own risk.
-
Bob
I am assuming you put this information in this thread because you believe the same EPA issue applies to Rustoleum's Painters Touch brand of paints. It sure seems to fit exactly what I experienced. Also I don't ever remember this problem with regular Rustoleum or their Painters Touch version in the past. This really caught me by surprise.
-
Bob
I am assuming you put this information in this thread because you believe the same EPA issue applies to Rustoleum's Painters Touch brand of paints. It sure seems to fit exactly what I experienced. Also I don't ever remember this problem with regular Rustoleum or their Painters Touch version in the past. This really caught me by surprise.
Rustoleum's Painters Touch is a enamel
-
I'll be painting my Yak-9, a T-28 and a friend's P-51 sometime this summer, so I figured it would be okay to bump this thread. It's titled "Rustoleum" but the discussion turned more to Krylon, which I've never tried. It doesn't look like I'll ever be trying it after reading the above posts.
I've always had good results with Rustoleum Automotive Enamel that I buy at Lowes. I always cover it after a couple of weeks with Lustrekote Clear gloss, and never had a wrinkling problem until this Winter when I painted my Shoestring red and black. Most of it came out okay but a couple of patches of both colors wrinkled. I figured I had just laid the Lustrekote on too thick, but when I scraped and repainted the same thing happened. Is there any chance I would have better luck with Rustoleum clear? I've never tried it and don't know if it's sufficiently fuel resistant. I usually don't get much raw fuel on the plane, but plenty of exhaust and I clean it thoroughly when I get it back to the shop. Has anyone had any experience with the Rustoleum clear? Should it be applied immediately on top of the color, or is a 24 hour or a two week wait better.
Some of you mentioned two part paint. Are you using an airbrush to apply that. I don't have that equipment, so I'm stuck with rattle cans.
Thanks,
Rusty
-
Consensus on this Forum is that Rustoleum clear is not fuel proof or even resistant and will leave you with a sticky mess. Can't say first hand but decided to take other's work for it. A search will bear this out. 8)
-
Consensus on this Forum is that Rustoleum clear is not fuel proof or even resistant and will leave you with a sticky mess. Can't say first hand but decided to take other's work for it. A search will bear this out. 8)
Actually I did. Sorry for prematurely bumping the thread. I'll stick with Lustrekote and try to be light handed with it.
-
You just really have to be careful over coating and enamel paint. My flight box, had a spot were the paint was failing. So scrape up the loose stuff sand it clean it and shoot it with the same can of rustoleum I used last year.
Shoot it on nice and thick, hell it is a flight box right? Even though the paint is well over a year old, the paint blistered badly in a expanding circular defect. Now my dime sized repair is 2 inches in diameter.
Wiped it off with a rig soaked in thinner. Many light coats followed. and it did not blister. Good. One last thick coat and CRAP it was a mess all over again. So the solvent is pretty strong and will get under old paint if laid on too thick.
So only over cote with many very light coats. I am looking to switch away from spray can enamels.
I have had the same issue with Luster kote over rustoleum as well only thing coats will work.
-
So is Painters Touch as fuel proof (resistant) as Rustoleum or the new Krylon? Yes, not clear or metallics.