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Alclad help
Thundergrunt
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California, United States
Member Since: November 01, 2009
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Posted: Saturday, December 10, 2016 - 10:47 PM UTC
Hey All

I'm just coming back to the bench after about 4 years away. And working on my second model. 1st one not gonna post was horrendous. Anyway was trying to spray some alclad and both times I got like 3 secs and the clogged up. AB. Broke it down cleaned again and tried and same thing. I cranked up air pressure to like 30psi that got it going but was way to much. What do I do? I am trying to spray exhausts and gun ports on a 1/48 P51. Thanks.
Kevlar06
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Member Since: March 15, 2009
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Posted: Sunday, December 11, 2016 - 08:13 AM UTC

Quoted Text

Hey All

I'm just coming back to the bench after about 4 years away. And working on my second model. 1st one not gonna post was horrendous. Anyway was trying to spray some alclad and both times I got like 3 secs and the clogged up. AB. Broke it down cleaned again and tried and same thing. I cranked up air pressure to like 30psi that got it going but was way to much. What do I do? I am trying to spray exhausts and gun ports on a 1/48 P51. Thanks.



Hmmm...I'll stop short of saying I'm an expert at Alclad, but I've been using it steadily for natural metal surfaces for over 10 years now, and I've never had a clogging problem-- at any air pressure. I have about 30 bottles of various metallic and clear colors, and spray them anywhere from 8-22 PSI. The higher air pressure allows you to get a lot on without it "powdering" on the surface, but frankly I like to spray it in small amounts at about 12 PSI. Alclad requires complete mixing, and should be shaken, not stirred-- preferably in a paint shaker, but you can do it by hand. I assume you are referring to the colors themselves-- not the base coats, but it shouldn't make much difference-- both are designed to be sprayed without thinning. Are you using an incompatible thinner perhaps? is your AB completely clean without an obstruction in the nozzle?
VR, Russ
Thundergrunt
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Posted: Monday, December 12, 2016 - 02:01 AM UTC
Russ

I was using my Mr' Hobby Airbrush at about 20 PSI. Not thinned the first time and shook for about 2 min. 2nd GO was thinned with laquer thinner as many have to use. I clean AB after every spray. I tried Burt Iron, and pale burnt metal.
Kevlar06
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Posted: Monday, December 12, 2016 - 06:10 AM UTC

Quoted Text

Russ

I was using my Mr' Hobby Airbrush at about 20 PSI. Not thinned the first time and shook for about 2 min. 2nd GO was thinned with laquer thinner as many have to use. I clean AB after every spray. I tried Burt Iron, and pale burnt metal.



Eugene,
I recommend you check the bottom (turn the bottle over and look to see if any paint is visible in the bottom) of the Alclad bottle after shaking. If there is any residue in the bottom, it's not mixed properly, and you might be getting a "chunk" of unmixed paint into your airbrush nozzle somehow--especially if you use a stirrer to mix it up--that's why it should not be stirred (It's like James Bond's Martinis- shaken, never stirred"). I've heard of folks using lacquer thinner to thin Alclad before, but it really doesnt need it, unless the paint has hardened in the bottle-- if that's the case, get rid of it and buy a new bottle. I've done it myself one time, but was not pleased with the result as it changes the formulation and the "grain/texture" of the paint-- I use lacquer thinner for cleaning my airbrush, but I never thin Alclad.
VR, Russ
Thundergrunt
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California, United States
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Posted: Monday, December 12, 2016 - 11:00 PM UTC
Ok Roger that never thin alclad. I shake them I even put a couple non corrosive BB's in there to help the break up like you said in the bottom, I saw in a Spanish modelers video. My question is now. What psi should I be using?? And is it to cold to spray. I tried spraying at like 10psi to get a fine line but just can't do it and noticed when I let off a lot of paint splatter. Or when I am spraying g I get a couple lasers and then nothing. Just air. And the cup has bubbled a couple times. So I am thinking Psi and distance is off. You think.
Kevlar06
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Posted: Monday, December 12, 2016 - 11:53 PM UTC

Quoted Text

Ok Roger that never thin alclad. I shake them I even put a couple non corrosive BB's in there to help the break up like you said in the bottom, I saw in a Spanish modelers video. My question is now. What psi should I be using?? And is it to cold to spray. I tried spraying at like 10psi to get a fine line but just can't do it and noticed when I let off a lot of paint splatter. Or when I am spraying g I get a couple lasers and then nothing. Just air. And the cup has bubbled a couple times. So I am thinking Psi and distance is off. You think.



Eugene,
The symptoms you describe point to a blockage or needle problem somewhere in your airbrush or a faulty air supply. I've been airbrushing for 50 years with various airbrushes, and a "splatter" and irregular airflow is usually an indicator of a nozzle problem or an airflow problem. I'm not familiar with the Mr. Hobby airbrush, but I assume it's likely similar to an Iwata or like brush-- which I don't use. I have a Peak C-5, Paasche Millenium, and a Badger 155 Anthem along with about 10 other Badger and Paassche products I've used over many years. Whenever I have a splattering problem I look for the culprit in the nozzle, around the trigger mechanism, the trigger valve, or in the air supply. Usually it's a paint build up or chunk of paint that resides in the cup, migrates to the nozzle and temporarily blocks the needle opening. On rare occasions, I've discovered a split or damaged nozzle or needle, which can also cause splattering. You may need a magnifying glass to discover if you have a problem there. I recommend a complete tear down of your brush and a careful cleaning and re-assembly. You might also check the paint by filtering it through a nylon stocking or similar screen, to see if the paint has gone bad. A few years ago when I worked in a LHS, we had a shipment of Alclad gold leaf which came in a plastic bottle, and we noticed three or four of the bottles had softened and he paint inside had solidified a little. I tried to use one of the bottles in an experiemetn and found they had gone "chunky", and could not be properly mixed or sprayed. Our supplier replaced them, but I have not seen the paint come in a plastic bottle since (clearcoats do, but not paint). You may have a bad or old batch. I see you are in California-- I doubt being to cold is a problem, I'm up the coast a bit, and work in my garage in the winter (I do have a space heater, but in the winter I am painting at temps between 50 and 70 degrees at the most) and I've never had a problem with Alclad. 20 PSI is an acceptable air pressure for Alclad, although I prefer @12-18 PSI. One other thing you might check is your compressor fittings and hose, if your compressor is "pulsating" you can also get "splatters". A tank compressor is best, as it gives an even PSI, whereas a plain piston compressor has to compensate for the movement of the piston, which causes the pulsating. That, in combination with a leak in the hose or brush can cause a decrease in pressure at the nozzle end, resulting in momentary paint build up, which becomes a splatter". Alclad is pretty forgiving paint, right out of the bottle, but it can be finicky with a dirty brush or a faulty air supply. One other thing-- if you don't have a water trap, water build up can also block the airflow or get into your brush, causing splattering problems. You also mention air bubbling in the cup-- that's usually a good indicator of a brush problem, not a paint problem. have you tried a different kind of paint in the brush (thinned to the consistency of Alclad) to see if the same problem occurs? My rule of thumb for mixing paint for fine lines is 30/70 at about 8-12 PSI-- 30% paint to 70% thinner (Alclad of course uses no thinner).
VR, Russ
smeosky
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Member Since: November 22, 2010
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Posted: Thursday, December 22, 2016 - 09:19 AM UTC
I routinely have issues painting w alclad out of all 3 of my brushes. My paasche H is the worst. It almost instantly dries in the tip at various pressures and.only does OK if I have the nozzle set to wide open. My Iwata eclipse with its small needle gets finicky too and dries up pretty regularly. My paasche millennium w the .4mm tip works the best but I still have to clean the tip off pretty often. I'm usually at 9 to 25 psi and am almost positive I don't have any clogging /mechanical issues. All brushes spray tamiya, clear coats and laquers just fine so I have no idea why I don't get along w the stuff. One habit I have is to spray too fine a pattern so perhaps alclad is better suited to heavier applications. Another thing that's helped a lot for me recently is not pushing the needle in too tight after cleaning. Press it in firmly enough to just seat it in place. No more no less.
Kevlar06
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Posted: Thursday, December 22, 2016 - 11:50 AM UTC
Hmmm... I've routinely sprayed Alclad for nearly ten years now-- first the original and now the Alclad II colors, and I've never had a problem. I use a Paasche Millenium, bottom feed cup, a Badger 155 Anthem bottom feed cup, and a Peak C5 gravity feed cup-- for fine work I prefer the Peak. I use an Aztec tank compressor with a Chinese made water trap and pressure regulator, but occasionally I also use a Thayer and Chandler (50 years old) straight compressor or a Badger compressor (also 50 years old) I've never had any problem with any of them spraying Alclad. As I said before, Alclad has a tendency to settle in the bottom of the jar-- the only problems I've ever had was when I didn't thouroughly mix it. I do use a Robart mini paint shaker to mix each bottle and when I do that I don't have any problems. I usually spray from 8-18 PSI -- I find paints dry faster at higher air pressures. I wonder if temperature or humidity can be affecting your Alclad?
VR, Russ