Hello, greetings, and a quick question (prop the first of many)

[5letters]

Salutations and much love, respect and good vibrations.

I've been in visual art for most of my life, now getting into airbrush (and loving it) and I have just started painting my first motor cycle. Before that the small jobs I was always only doing the actual artwork, which is my preference.

This time around some things happened, and I was left to do some touch up work... so I have been sanding it down on the metal with 400grit wet, 1000grit wet on the good clear, and putting primer on, sanding it with 600grit wet, and now I am putting dark sealer on, mostly to give it a uniform base color.

And as I am putting on my third wet coat (first two, just tack coats) and it is drying I notice that it isn't smooth!!? Not a huge tooth to it, but definitely not a baby's butt (if you take my meaning).

Is it normal, or am I missing something? Should I sand it down with 2000grit? in which case, wet or dry?

Any feedback is appreciated!!

Some info that will help you:

I use Harder Stenbeck Infinity with autoair / wicked. Clear is going to be toxic, but I prefer my paint waterbased.

I don't have an airgun, so the primer went on from can, the sealer from my 0.6 needle/nozzle setup.

I'm in montreal, and this time of year, either it is dry and cold, or humid (and cold-ish) so I use a heat gun to cure the paint. So far I have been giving it 25 - 40 minutes between each coat.

I hope someone is going to be able to give my some feedback, and let me say I am happy that forums like this exists! Thanks!!

Bjørn

 

[Mr.Micron]

You really need a mini jet toush up guns , The fan pattern helps with an even coat where your .6 airbrush is putting out a round pattern which can give the bump effect you are talking about.
Being you state you use water based paint system I assume you are referring to the AutoAir dark sealer? If so what is the temps in the shop area you are spraying in? Anything below 60 degrees makes it do funky things (found out the hard way)
Also are you using the AutoAir reducer or a home brew?

Oh and welcome home.

 

[5letters]

One step at the time

 

[5letters]

I think it figured it out, so here goes:

Mr.Micron! Thank you for taking the time to answer. I think you just explained to me my problem - as I have been spraying in less than 60 degrees

I know I need a touch up gun (finding out the hard way Iu guess) but I am unsure if Ineed a new compressor to go with it. Right now I got the Iwata Power Jet, it's got 1/6 horse power, 3.5 litre (almost a gallon) tank, 1.2 CFM (at) open flow, max 70 PSI. All that is official specifications. I never had it higher than 45 PSI.

Do you think it could handle a small touch up gun? If yes, would you recommend something (if that is allowed here on the forum)?

If no, what kinds of specs would you say I am looking for in a compressor, to handle a touch up gun?

Yes, I am using AutoAir Sealer Dark, and on the subject, since the studio has been less thatn 60 degrees, should I warm up the sealer (and the paints, mostly Wicked) before I use them? Maybe a better question is, what temperature would you recommend for the shop and for the paints / sealers?

I am using the 4011 reducer, 3:1 paint to reducer ratio for the sealer.

I tried sanding the sealer down, but if came off kind of rubbery (I had given it a 2,5h curing time, with heat gun on - so the shop became warmer, prop 65 degrees) and when I took a kitchen towel with pre-clean to it, tons of fluff got caught in the texture of the sealer. In my frustration I loaded a lint free towel with clean water in an attempt to wash it off. Not a great success AND I read just after that, that AutoAir is NOT to be cleaned with water like that.

So please tell me, should I take it back down to the metal, or is it enough just to sand it down until smooth and build it up again with even thinner coats?

I hope you make sense of my situation, and I look forward to your input!!

Thanks for the welcome home

B

 

[Mr.Micron]

I think it figured it out, so here goes:

Mr.Micron! Thank you for taking the time to answer. I think you just explained to me my problem - as I have been spraying in less than 60 degrees

I know I need a touch up gun (finding out the hard way Iu guess) but I am unsure if Ineed a new compressor to go with it. Right now I got the Iwata Power Jet, it's got 1/6 horse power, 3.5 litre (almost a gallon) tank, 1.2 CFM (at) open flow, max 70 PSI. All that is official specifications. I never had it higher than 45 PSI.

Do you think it could handle a small touch up gun? If yes, would you recommend something (if that is allowed here on the forum)?

If no, what kinds of specs would you say I am looking for in a compressor, to handle a touch up gun?

Yes, I am using AutoAir Sealer Dark, and on the subject, since the studio has been less thatn 60 degrees, should I warm up the sealer (and the paints, mostly Wicked) before I use them? Maybe a better question is, what temperature would you recommend for the shop and for the paints / sealers?

I am using the 4011 reducer, 3:1 paint to reducer ratio for the sealer.

I tried sanding the sealer down, but if came off kind of rubbery (I had given it a 2,5h curing time, with heat gun on - so the shop became warmer, prop 65 degrees) and when I took a kitchen towel with pre-clean to it, tons of fluff got caught in the texture of the sealer. In my frustration I loaded a lint free towel with clean water in an attempt to wash it off. Not a great success AND I read just after that, that AutoAir is NOT to be cleaned with water like that.

So please tell me, should I take it back down to the metal, or is it enough just to sand it down until smooth and build it up again with even thinner coats?

I hope you make sense of my situation, and I look forward to your input!!

Thanks for the welcome home

B

Iwat mini jet touch up gun run about 135.00 US. But look around you local paint stores and see what they have to offer in an HVLP (High Volume low pressure) touch up gun.
As far as your compressor it should do fine on motorcycle tins 40 PSI is the max pressure I run on anything be it airbrush or spray gun.

Shop temp should be 70 degrees , The reason for the rubbery seal coat is due to low heat. If you can not heat you work area to 70 than buy a good heat gun and cure the paint that way. It is also know as heat setting the paint.
When Autoair comes out rubbery it is due to not being cured and set 100% which in the long run would make for a bad paint job.

As far as taking back to bare metal that will depend on how it sands out. if you can get a good smooth surface on it than no need to , But it is comes off to bare metal than yes.
I always start with a self etching primer on any metal , That ensure a good tooth for the other paint to adhere to . Than when I am using Autoair I used a dust coat, heat gun than dust coat, heat gun and build the sealer slowly allowing good time and heat for it to cure.
That is the secret to Autoair. build slowly and use heat. A hair dryer works great.

 

[Strictly Attitude]

First welcome to the forums!! Next your problem defintely get a small spray gun will pay for itself with less agrivation and great tool to have in the arsinal. Next I'm not familiar with auto air sealer but know if use a quality automive 2k primer/sealer you will save allot of agrivation it sands nice and don't have to worry bout it getting wet. Also the spray gun will make short work of your base coat. I use wicked paints personally and when I do a bike I try to use automive uro's for my primer/sealer and base coat. I like to also spray a few layers of intercoat clear to protect my base in case I need to sand or have a mishap. You can easily do your base with waterbase/borne paint and then intercoat to protect. If you don't have intercoat use regular clear then red scotchbrite pad or 600-800 grit wet sand before art work. Hope this helps a little

 

[5letters]

Thank you both for taking the time to answer!!

Yeah, i will try to heat the shop more, give longer curing times and with the heat gun on... how long would you say for a thin coat of auto air? Or is there any way to tell? - obviously the surface appears dry when I put the next layer on...

Also, you said that not properly cured paint leads to a bad paint job. If I am able to sand it down to a smooth surface is that proof that it has cured properly? I would like not to take any chances due to the 350lb Harley owner rule... :/

About the spray gun. When I read specifications they say something like 1.8 CFM at 36 PSI - which is what has got me unsure, as mine is 1.2 CFM at open flow (which I don't know what means) and a max of 70 PSI. If is means that open flow is max PSI then it should stand to reason that if I went with 40 PSI then it should easily produce 1.8 CFM!? Can you guys confirm this?

Also, looking at coast airbrush dot com they have an iwata eclipse G3, G5, and G6 which they say operates like a large airbrush, but can give an oval spray pattern for backgrounds / bases - and that it works well with the power jet compressor. But it costs more (about 350 us for the G6), and I've read that it is not very versatile. Do you have any opinion about this?
Also, it is noteworthy that they specify that these guns works well with the power jet, but they don't say that with any other gun, like the LPH80 HVLP mini center post spray gun (where they say low PSI and 1.8 CFM).

About intercoat clear. Right now I have (but haven't used so far) SEM Art Seal inter-coat clear, but I have read that it is possible to use a transparent base (AutoAir) instead. Do any of you guys have experience with this?

Oki, thanks for your time, and I look forward to hearing back from you! Now of to sanding!!

Bjørn

 

[5letters]

One other thing,

when I sand down the sealer, I cannot wet sand it? As I've read I shouldn't clean auto air with water, I guess that also means no wet sanding? Can you guys confirm?

Thanks so much, it is amazing that there's people willing to help those (like me) with less experience!!

Bjørn

 

[Mr.Micron]

If AutoAir is 100% cured wet sanding is not really an issue. But being it was not heat set , Heat setting between coats is mainly taking the heat gun across it until you see no damp spots or discolored areas, Sometime is only take a couple of passes sometimes it can take a little longer. I use Terry Hill's rule of thumb, Pass the heat gun at a slow pace for 3 minutes.
By discolored I mean you can see if it is damp due to it look darker in the areas that are damp.
The compressor you have should handle a mini touch up gun with the spec you have.
the Trans base does help semi protect the paint job but than again it is still a water based paint. So I always use House of Kolor SG100 intercoat clear. That way my base coat is fully protected when I start laying on my art work. Than intercoat clear the artwork than 2k clear the entire piece .

 

[5letters]

Shop temp should be 70 degrees , The reason for the rubbery seal coat is due to low heat. If you can not heat you work area to 70 than buy a good heat gun and cure the paint that way. It is also know as heat setting the paint.
When Autoair comes out rubbery it is due to not being cured and set 100% which in the long run would make for a bad paint job.

As far as taking back to bare metal that will depend on how it sands out. if you can get a good smooth surface on it than no need to , But it is comes off to bare metal than yes.

So I am dry sanding with 1000 - 2000 grit sandpaper, and it does get smooth. However, it continues to be rubbery. The shop has been more than 70 degrees for about 6 hours now.

Will the sealer cure over time? Should I wait with sanding until it is completely cured? Or will it not cure if it hasn't already cured? In which case I wring back to scratch...

Thanks, and I look forward to your reply!

Bjørn

 

[5letters]

If AutoAir is 100% cured wet sanding is not really an issue. But being it was not heat set , Heat setting between coats is mainly taking the heat gun across it until you see no damp spots or discolored areas, Sometime is only take a couple of passes sometimes it can take a little longer. I use Terry Hill's rule of thumb, Pass the heat gun at a slow pace for 3 minutes.
By discolored I mean you can see if it is damp due to it look darker in the areas that are damp.
The compressor you have should handle a mini touch up gun with the spec you have.
the Trans base does help semi protect the paint job but than again it is still a water based paint. So I always use House of Kolor SG100 intercoat clear. That way my base coat is fully protected when I start laying on my art work. Than intercoat clear the artwork than 2k clear the entire piece .

Thanks!! I will go ahead and get a mini touch up gun That way I can prime, seal, do base, intercoat clear and clear without the issues of cans and airbrushes gives when applying this!

I didn't not time it, but I think I let the heat gun blow on it from about a foot and a half away (it's the side of the tank that is down to the metal, like 1½ wide and ½foot top to bottom) for at least ten minutes!

And like said, shop temp has been higher now, above the 70 degrees, yet it doesn't seem completely cured, as it is still rubbery... what are my options in your opinion?

Thanks though for letting me know that once 100% cured I can wet sand it...

 

[Mr.Micron]

Thanks!! I will go ahead and get a mini touch up gun That way I can prime, seal, do base, intercoat clear and clear without the issues of cans and airbrushes gives when applying this!

I didn't not time it, but I think I let the heat gun blow on it from about a foot and a half away (it's the side of the tank that is down to the metal, like 1½ wide and ½foot top to bottom) for at least ten minutes!

And like said, shop temp has been higher now, above the 70 degrees, yet it doesn't seem completely cured, as it is still rubbery... what are my options in your opinion?

Thanks though for letting me know that once 100% cured I can wet sand it...

Just remember light handed sanding .

 

[5letters]

Just remember light handed sanding .

Thanks, that was something I didn't know!! Maybe that was why the paint came off rubbery?!?!

So am to understand, that you're saying that given enough time the sealer will eventually cure a 100%??

Bjørn

 

[Mr.Micron]

Thanks, that was something I didn't know!! Maybe that was why the paint came off rubbery?!?!

So am to understand, that you're saying that given enough time the sealer will eventually cure a 100%??

Bjørn

Yes, Back in the Enamel paint days paint could take up to a month to cure. That came harder and reducer for faster dry time and more durable paint jobs.
With AutoAir you have that build in except the dry time may very due to humid conditions , Cool or cold temps and air flow over the piece.
Now I have painted when temps have been in the 40's But I would set up space heaters all around the piece so the cold air did not effect the paint as it came out the airbrush.

 

[5letters]

Yes, Back in the Enamel paint days paint could take up to a month to cure. That came harder and reducer for faster dry time and more durable paint jobs.
With AutoAir you have that build in except the dry time may very due to humid conditions , Cool or cold temps and air flow over the piece.
Now I have painted when temps have been in the 40's But I would set up space heaters all around the piece so the cold air did not effect the paint as it came out the airbrush.

Wow, a MONTH!!! Thanks for the info, I am curious by nature and learning new stuff about the evolution of stuff I am passionate about is a great pleasure for me!!

Also, the lighthanded sanding made a difference!! and now the heat gun is on and I am going to give it another 12 hours and then I think it is properly cured, then on to base coat and finally (yay) the artwork!!!

Wishing you a great and creative productive day!!

Good vibes

 

[Mr.Micron]

Wow, a MONTH!!! Thanks for the info, I am curious by nature and learning new stuff about the evolution of stuff I am passionate about is a great pleasure for me!!

Also, the lighthanded sanding made a difference!! and now the heat gun is on and I am going to give it another 12 hours and then I think it is properly cured, then on to base coat and finally (yay) the artwork!!!

Wishing you a great and creative productive day!!

Good vibes

Glad I could help and unless you are working bondo always use lightedhanded sanding...