After finding that my airbrush works MUCH better when I have the nozzle in, see my post DOH!!!, I started trying to work with it some more. I found that it was painting but I still wasn't getting the volume I thought I should. I'd been using the bottle with the cap and tube and using 50/50 mix of denatured alcahol and Tamiya acrylic. I thought I'd try the open topped hopper thing. Works MUCH better. Same paint, same paint mixture, same compressor preasure, vastly different results. Any idea why the hopper works better than the cap and tube thingy?

Hey Rodger -
Presumably its that it is gravity fed and not vacuum fed or a result of the venturi effect, and everything I have ever read about painting says for paint to 'flow' onto the model.

What is "denatured alcohol" I asked for some at the pharmacy section of WalMart and all they could offer was isopropyl (rubbing) alcohol. Is it the same thing?
I didnt get any because I wasnt sure...

Firemann816

Hi Firemann816
I asked myself that same question and NO they are not the same. I have seen denatured alcohol only in hardware stores. I have never seen it at my local pharmacy.
Good Modeling!

Denatured alky is just regular booze thats been screwed up with a chemical that makes you throw up. Basically its Ethanol - same as in your whisky, rubbing alcohol is Isopropanol.

I think they call denatured spirits methylaed spirts in the UK - dont know about the US

(I hope i haven't put my foot in my mouth here )

Hi there

I'd always thought de-natured Alcohol and Isopropyl Alcohol were the same thing.

Rubbing alcohol sounds like what we'd call "surgical spirits" in the UK.

Metholated Spirits is dyed purple to discourage people from drinking it, and isn't the same stuff as Iso...

I love our terminology mix ups! :-)

Rowan

I know ethanol is whiskey, I'd rather have it flavored with a malt, than from the hardware store, but I guess it takes all kinds.
I know isopropyl is used as "rubbing alcohol" in USA. We put it on insect bites, scrapes, etc, and burns like hell. Hydrogen peroxide is better on scrapes, etc because it disinfectes without the agonizing pain.
The denatured is new to me, but I'll look when i'm at the the hardware store next time.
I didnt think of thinning Tamiya Acrylics with it, but have heard it is a good thinner for Future.
Can anyone confirm thinning Future with it?
Is this product used because it has a low flashpoint and evaporates away?

Thanks to all for the comments
Regards
Firemann816

Dont know what "denatured alcohol" is either but I use Isoproponol all the time for thinning tamiya paints. Works well and dries fast!

Ethanol ......... does this work. We use this at work and I have a lifetime supply for free if this works ......... anybody use ethanol for thinning?? Please let me know.

Rodger,
Back on topic: The reduced flow when using a covered bottle is due to less air being able to get into the paint reservoir because of the top. The open topped hopper lets all the air it wants in, while the top, even if it has an air hole, restricts the air flow and causes a vacuum effect that doesn't let the paint go into the airbrush. Same effect as holding your finger over the end of a straw and pulling it out of a liquid, the liquid will stay in the straw. Check to see if the air hole in your bottles top is unblocked or if it even has one, you shouldn't really be able to notice a difference. You may want to expand the hole if it has one or drill one if it doesn't to help the paint flow into the airbrush better.

I don't know why but somebody once a long time ago introduced it to me as "Denatured Alcahol" and that's how I've referred to it. Reading the label I do see it's isopropyl alcahol that I picked up at a dollar store.

Tim, the cap doesn't have any kind of hole in it, other that where the paint comes out. I think what you said makes perfect sense. It seems to me that is DOES need a hole in it to let it flow properly, someting like the old oil cans where you had to put two holes in them to get them to flow properly. This cap sure isn't working well now, and they're not too expensive, I think I'll try a little corrective surgery on it tonight. Thanks for the tip.

Denatured alcohol, as I understand it, is SERIOUSLY POISONOUS, and will hurt you more than merely making you vomit.

Thinning Tamiya with Future? I have done so and was not pleased.

Tamiya did thin and spray GREAT with Polly Scale gloss.

I just looked at my can of denatured alcohol and it says it is Ethanol denatured (what ever that means) with Methanol. It is flamable and poisonous. It is also used to thin shellac but I don't know if asking for shellac thinner would get you denatured alcohol. I started using it when I started using acrylic paints on a recommendation from somebody, I find it flows better onto plastic compared to using just water, I also use it to clean my brushes when water alone doesn't seem to be working, I use Windex or ammonia when that isn't enough.

Rodger:

One other problem I thought I would mention before the sugery is the pick up tube in the jar may not be seating properly. If it is lose, has a pinhole or crack in it. This may affect the pick up of paint. HTH

Paul

If anyone is interested in viewing these pages, here are links that describe the contents, flash points, volitility, lethality or danger to humans, and many more chemical aspects of Denatured and Isopropyl Alcohols (which, by the way, are very different)


Denatured Alcohol


Isopropyl alcohol
Isopropyl alcohol

[quoteTim, the cap doesn't have any kind of hole in it, other that where the paint comes out. . [/quote]

There's your problem
Add a pin hole to the cap, to allow air in.

In the name of keeping two threads in one going:
From the MSDS Sheet posted above -
Section XVI - Other Information
Synonyms/Common Names: Denatured........Ethanol, Ethyl Alcohol, Special Industrial Solvent 190, Grain Alcohol

It is grain, but I'm also sure the post about it being poisonous is true, since its intended use, isnt to replace your Scotch with. They probably add other helpful solvents to the recipe, but they alll had names way longer and more complex than "denatured alcohol"

I appreciate the post from the gentleman who advised ti seems to thin Acrylics even better than water.

Roger, dont forget to add your vent hole, and let us know that works out in comparison to the gravity cup, (hopper thingy)

Regards to all
Firemann816

I actually tried thinning Tamiya paints with Smirnoff Blue Vodka(50% vol, 100`proof) It worked just fine....

Also it helps keep the spirits up since you can take a nip of th thinner now and again while modelling #:-) Sorta keeps the morale up.

Actually, I just went back and checked my chemistrybooks, Ethanol a.k.a. Ethyl Alcohol is the "active ingredient" in your regular booze, be it vodka, whisky, beer or wine. However - DO NOT DRINK DENATURED alky, that stuff is only intended for industrial and medical use (and thinning paint).

That is single most useful suggestion I've ever seen on this board. Do you suppose it would work with Bacardi 151 rum, 151 proof, about 75% alcahol? After a few "nips" of THAT stuff who cares if it sprays or not.