Can anyone tell me why the testors dull cote rattle can is producing the the spotty finish as shown below? There was a coat of testors gloss coat applied prior with no noticeable spots before the dull cotewas applied. The gloss coat was allowed to dry for over 3 days before applying the gloss coat. I did some searches online and didn’t really learn anything to address this.
Thanks!
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It looks to me like the spray itself came out very uneven, possibly from having a low pressure inside the can, or partially clogged nozzle.
I don’t know if I’d apply a second wet coat ....you might chance forming wrinkles in both layers of existing clear coats,.....Mike, how many coats of Dullcoat have you applied?....were there any possible impurities on the roof before the Dullcoat went on?.......when this happens, the easiest remedy is to LIGHTLY scuff the smooth areas with fine scotchbrite ( grey or red) wipe the roof down with a clean microfiber and visual inspect for flaws or fuzzies left behind,.....once you’re satisfied the roof is slick & smooth, apply one even MEDIUM coat in one motion and observe the finish,....a hairdryer speeds up the curing process,.....inspect your work and either repeat the scuffing process or apply one more medium coat in one fluid motion to lock it in,......also, test your can on a piece of scrap to be sure it’s not spattering,.......I’ve long since stopped using Testors Dullcoat in favor of Krylon’s flat clear....that product comes out at a higher pressure than Dullcoat, and the can lasts ten times longer for less money,....
Pat
Spraying dullcote with a lot of humidity in the air can make if fog and do strange things.
My theory. Dullcote is a lacquer. I assume Testors gloss cote is also a lacquer. Dullcote in a spray can comes out very heavy. It may be attacking the gloss cote at different rates. I have had much better results with dullcote in an airbrush using light coats.
Pete
Thanks guys,
I believe there is plenty of pressure in the can and i do not observe any spitting or unusual spray when it goes on.
I have put another couple of coats where the entire surface looks wet, and it is still drying with same surface. I was sure to shake the can excessively and I am painting in 50% humidity.
Being the model is wood, stripping the paint is not really an option I am excited about.
Wondering if there is a better product before I paint the bottom of the caboose that may not cause the same issue, but be compatible with the testors gloss coat already on there. I have had bad luck with rattle cans from big box store causing crinkling when applied over its self or a other colors of the same brand.
I've never had much luck using Dulcote from a rattle can. Lots of time it leaves a mottled finish although every once and a while it comes out good. Like others said humidity has a bad effect on it but I think the main problem is in the nozzle. The spray droplets are too large using the cheap nozzle. I always use an airbrush with Dulcote. Thin it about 25% first, use an external mix airbrush at about 30 pounds pressure. This results in a very fine spray so it goes on evenly and dead flat.
Ken
@Hump Yard Mike posted:Thanks guys,
I believe there is plenty of pressure in the can and i do not observe any spitting or unusual spray when it goes on.
I have put another couple of coats where the entire surface looks wet, and it is still drying with same surface. I was sure to shake the can excessively and I am painting in 50% humidity.
Being the model is wood, stripping the paint is not really an option I am excited about.
Wondering if there is a better product before I paint the bottom of the caboose that may not cause the same issue, but be compatible with the testors gloss coat already on there. I have had bad luck with rattle cans from big box store causing crinkling when applied over its self or a other colors of the same brand.
As Pete mentioned, your best results will come from a gun, such as a half descent airbrush........you’re removing the propellant variable and now you’re in control of pressure, and volume of material,.....all you can do with a rattle can is push the button,...😉
Pat
I have a decent air brush (iwata) but not clear why the results would be any better using it if the paint is the same lacquer ? If I did use the air brush, I was planning on using the stuff below but need to pick up some lacquer thinner. Has this stuff worked well for you?
Mike, yes,...the results from a gun will be far better than from a rattle can,...rattle can paints use propellants to get the material out of the can,...those propellants are mixed with the paint, strike one, you can not control the volume coming out of a rattle can, strike two, .....you can not control the pressure coming out of a rattle can,....strike three,......practice with your Iwata, play with the reductions, the pressures and the volume you’ll notice the finishes will be dramatically different from a gun vs a can,....the biggest advantage of an airbrush in this hobby to me is the ability to apply a pin point amount of paint in the smallest area,....you ain’t doing that with a rattle can ,....at least not with out a lot of back masking,...😉
Pat
If I was going to attempt to remove the paint, are others use 409 or something else?
Before you do anything drastic like trying to remove the paint chemically or with sandpaper, get some of the Dulcote in a bottle and some lacquer thinner. Mix up the Dulcote with 25% thinner and practice with your airbrush on some old models from your junkbox. After you feel like you've got airbrushing down, spray your caboose with very light coats letting them dry for about 10 minutes between coats. Don't overdo it don't let the surface get very wet. It just may get rid of the mottled appearance. I've done this before and have had some success. However it was years ago before when I decided rattle cans were hopeless if you wanted a good finish.
Ken
@Hump Yard Mike posted:Can anyone tell me why the testors dull cote rattle can is producing the the spotty finish as shown below? There was a coat of testors gloss coat applied prior with no noticeable spots before the dull cotewas applied.
Curious as well since I just had a reverse experience where the gloss (I was added it to do the decaling) over the paint over the primer that had been drying for 2 weeks plus lifted both layers of paint right down to the brass. I've not ever had that happen before. Beginning to wonder about all sorts of changes in formulation.
@Hump Yard Mike posted:If I was going to attempt to remove the paint, are others use 409 or something else?
Before I went that drastic, I would use a magic eraser very lightly to go over this area. Should work fine to remove those spots. And in my opinion, stay clear of rattle cans if at all possible. They do cause these issues from time to time-- especially given you have an airbrush to use. Just my opinion...
@Hump Yard Mike posted:
I have a decent air brush (iwata) but not clear why the results would be any better using it if the paint is the same lacquer ? If I did use the air brush, I was planning on using the stuff below but need to pick up some lacquer thinner. Has this stuff worked well for you?
Besides the points Pat makes, by using an airbrush with a finer spray and lacquer thinner you can hold the airbrush further back so the paint goes on dryer. Normally you wouldn't want to do that with a gloss or satin finish but in this case you want a flat finish and this will accomplish that with less paint than that rattle can will apply.
Pete
I stopped using T.D.C. a few years back for weathering. Spotty texture is good for what I do. If the spots are large, clean the nozzle. I just use it now only over decals. Seems they changed the formula and also raised the price. It has a satin shine since the change and is no longer flat.
Use Krylon clear flat as a substitute. I buy it by the box / case at Lowes. A large can goes a long way with a lower material cost as well.
Fifty years ago Krylon was great! About 20 years ago they changed the nozzle and propellant, and I found its only use was on lawn chairs, and you had to use it all at once. No fair storing it for future use.
I would be delighted to find out that they changed back to a useful product.
@Jeff78rr posted:Before I went that drastic, I would use a magic eraser very lightly to go over this area. Should work fine to remove those spots. And in my opinion, stay clear of rattle cans if at all possible. They do cause these issues from time to time-- especially given you have an airbrush to use. Just my opinion...
Question: What is in MAGIC ERASER that removes all these stains and such. Inquiring minds want to know
Tamiya dullcote is the only one I use. The sacall it a synthetic laquer. Never a problem. I gave uip on solvcent based and Testors. Humidity will work against you as previously mentioned.
@Bryant Dunivan 111417 posted:Tamiya dullcote is the only one I use. The sacall it a synthetic laquer. Never a problem. I gave uip on solvcent based and Testors. Humidity will work against you as previously mentioned.
Bryant, you hit the nail right on the head. The Testors Dullcote of today is different somehow. What used to be a very forgiving dull coat has turned into an often problematic spray. I would advise Mike to gently sand the area with very fine steel wool and apply Tamiya Dullcoat. The Tamiya is hands down a better product, and has never reacted badly to any type of paint base I've laid down... whether it be from an airbrush or a rattle can. I had used Testors for decades, but I fixed a F117 model that exhibited the same blotches on your roof by simply switching over to Tamiya. I didn't even scuff it up first. That made me a believer.
Again, stay from the stuff, its overpriced for a SMALL CAN and is no longer FLAT. 
@Hump Yard Mike posted:If I was going to attempt to remove the paint, are others use 409 or something else?
I would not attempt to remove any of the finish you’ve applied,....this can be remedied with a light scuff and a re-shoot,....I’m gonna rebut a couple of thoughts and I’m only speaking from practical experience, those that use these practices, if that’s what works for you, then so be it,...however, ..the Mr.Clean magic eraser....that’s loaded with soap,....ain’t no way I’d want soap being imbedded into something I’d want to re-spray, ....not a big fan of using steel wool either,.....personally, I think steel wool has no business being near anything model railroad related,...but that’s for another topic,....you’re attempting to make a repair, treat it as such,....as I’ve mentioned before, fine scotchbrite ( grey or red) should be a handy tool in your arsenal, if you don’t have scotchbrite handy, super fine sand paper such as 1000-1500 would do the trick,....all you’re looking to do is level out the modeled finish, and re-coat. Try not to break through to the color coat, work on top of your existing finish. I would only concentrate on the smooth areas of the roof, the walkways look fine, and the modeling doesn’t seem to show up on them,...I’d just lightly scuff them and wipe everything clean with a dry rag, inspect the repair for debris and smoothness, and re-shoot,.....super fine scratches left on the existing top coat will be covered by the proceeding coats of finish,.....I see no need what so ever to remove any top coat,...besides, didn’t you say that’s wood model??...definitely wouldn’t want anything wet near that!....can you say warp and curl??....😳
Pat
If a good coat is really important, I put the can in hot water for a couple minutes. Increases the pressure and the paint is thinner. I knew guys that did 12st rate model cars with this method.
Like Ken (kanawha) I've gotten mottled finishes with Dullcote as well. Pretty much stopped using it. Over the years, I heard a lot of people talking about Dullcote, and it seemed the product of choice, but when I started using it maybe 4 years ago, I frequently got mottled finishes, at least on plastic. I've used it to dull colored tape, for example, and it worked OK, but I won't risk using it on plastic or over existing paint anymore.
A good airbrush would be the best thing to use.
Warming up the Dullcote in a pan of hot water is a good idea.
Testors had Enamel in those spray cans also ( something I learned the hard way )...........the fast drying laquer base in Dullcote sprayed over slower drying enamel will make a crackle effect in your final finish that looks like your caboose roof. Gloss could have even been a slower drying laquer.
@SIRT posted:I stopped using T.D.C. a few years back for weathering. Spotty texture is good for what I do. If the spots are large, clean the nozzle. I just use it now only over decals. Seems they changed the formula and also raised the price. It has a satin shine since the change and is no longer flat.
Use Krylon clear flat as a substitute. I buy it by the box / case at Lowes. A large can goes a long way with a lower material cost as well.
I also use the Krylon Clear Flat now. It makes a nice flat finish.
Great tip thanks! I was wondering why my latest TDC didn't work on flattening out gloss coats when it did so well in the past.
Now I know.
Thanks from the response from all. First comment, a member posted to this post (missing now) to use 409 for stripping dull coat. This didn’t work and I dont recommend this. I ended up repainting the roof of the caboose again. I was torn on what product to use, so I tested most of the products out there using a base coat of black with testor’s gloss cote over it in simulating the base needed for decals.
The items in the test included:
-Testor’s Dull coat from the can
-Tamiya’s Dull coat from the can
-Krylon’s Matt finish
-Krylon’s Satin finish
-Tru color Dull cote
-Testor’s Dull cote from the bottle thin 1:1 with laquer thinner using an air brush.
The dull coat from the bottle and thinned, applied with an air brush worked the best. I didn’t have a test strip to show this, but here it is on caboose. It can be applied very thin.
I tried the krylon satin finish and it just destroyed the sample piece, but in fairness I did not wait the recommended drying time on the gloss coat.
Testor’s Dull coat was the worst of the samples show below. It left a similar spotty finish as I originally started this thread with.
True color dull coat (acetone based?) did an alright job but came out more satin. Still a little concerned using this as it seemed like it required allot and was afraid it might attack the gloss cote as when it was applied it seemed like it has various types of cloudiness on the sample.
The krylon Matt finish came out fairly nice. There was some very faint speckling to it, but very flat.
The Tamiya dull coat was very close to the krylon finish, very flat, but I think it looked a little less speckled and seemed to go on thinner.
If using a rattle can, My preference would be using the tamiya dull coat, followed closely by the krylon flat. Best results would be from the testor’s dull coat from bottle thinner and using an air brush. I commonly spray acrylics in my basement with out a paint booth but wearing a mask, this is just not a option with the testor’s dull coat using the airbrush. It produced a fog that hung around for 10 minutes. Going forward, I will be doing the dull coat with the air brush in the garage.
Looks decent Mike. Glad you have found a solution.
Just be very careful with the fog in your area. I used to run a ventilation fan when spraying but there was always a need to have incoming air also. I now use the outdoors when using sprays or any volatile products. Stay safe.
I bought this at hobby lobby and had only good results with it. Use their 50% off coupon and it’s about three dollars a can.
Several of our customers has tried Mr. Super Clear UV Flat on their O gauge trains and they like the results. Perhaps they will chime in with their end results with this product.....
https://jrjunction.com/product...r-clear-uv-flat-spr/
I have been using Mr. Super clear Flat UV for a couple of months now. I feel it is a better product than Dull Cote.
It has a better spry tip that puts a more even coat on your project, and with the UV protectant, it will not yellow over time like Dull Coat will. The Mr. Super Clear cans are lager which is good. Seems like the Dull coat cans always run out on me when I am almost done coating what I am working on, and at the end of the can, it always spits out larger drops that screws up what I am working on.
I am a Mr. Super Clean convert.
I still have a few cans of Dull-coat, and I’ve been warming it up in warm water. I just finished this today. Once I’m out, I think I’ll go to the Krylon or Super Clean.
@Artie-DL&W posted:I still have a few cans of Dull-coat, and I’ve been warming it up in warm water. I just finished this today. Once I’m out, I think I’ll go to the Krylon or Super Clean.
Well , whatever your processes were on this flat clear coat job Artie , it really looks good . 😉
Thanks, Joseph. I also try to find a day to paint that’s warm and low humidity, and I spray outside on my porch. The tanker is hard at work on my layout!
I found two of my Dullcote sources were out of it, and another shop said they were backordered on it since September! I also noticed my last can said it was made by Rust-oleum. Lucky l have some Krylon, which says it is made by Sherwin- Williams, who should know how to make paint products.
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