Using Liquitex Slow-Dri Retarder with MM Acryl Paint

Sage advice is ain't but this is what I know-I use MM Acrylics & MM Acrylic thinner-not bad results, but still some issues with tip dry.  I saw a YouTube on one of the modeling sites (Cybermodeler maybe?) and the builder was using Liquitex Slow-Dri & MM Acryl to paint mottle on a German plane.  Although I wouldn't do it this way, he put the thinner in the airbrush cup, then added two drops of Slow-Dri and then a few drops of MM Acryl and stirred.  Worked for him, but I would have mixed in a different container and then poured.  I guess the key is to mix the thinner & Slow-Dri and then add paint.  I bought a bottle of Slo-Dri but haven't tried it yet.....

I don't know where you are located, but if you are near a Hobby Lobby, you can take advantage of their 40% coupons and purchase the MM Acrylic thinner there.  Dunno about ordering it on line-you can sign up for their e-mail offers and use the coupons on line also.

I suppose that makes sense.  If you put the paint in first, then there could be a small amount of undiluted paint that gets into the siphon tube that won't have thinner or retarder in it, which could still cause the tip to clog.

I live in the Los Angeles area.  There used to be a Hobby Lobby nearby but it's no longer there.  Funny you mention coupons, I bought the Liquitex at Michael's with a 50% off coupon, which brought the price down from $9.00 to more reasonable $4.50 for a 4 oz. bottle.

As an alternative to the expensive MM acryl thinner, does anyone out there use straight isopropyl alcohol?  Or perhaps a mixture of isopropyl and distilled water?

FSM did an article on acrylic paints a couple of months ago-I'll try to go thru my stack of issues and find it.  It mentioned different thinners(water/alcohol/brand name) that were compatible with the different brands of paint.

You might try a search here-there is usually discussion about this type of thing.

Edit-I just did a quick search and found this:

/forums/p/83624/816374.aspx#816374

Sorry that it didn't paste as a hyperlink...something about Firefox that won't let me do that.

Thanks.  I did do a search but somehow missed that thread.  I'll give it a try.

Don't thin Acryll with alcohol, just use distilled water. Or tap water in a pinch. Acryll and alcohol will mix but thinning with alcohol will only increase tip dry. I use MM's Acryll thinner. I know it isn't inexpensive but it goes a long way unless you happen to get a really thick bottle of Acryll. The consistency does vary.

Far as I know there's two reasons for mixing the retarder with thinner first. One is that it mixes more readily with thinner/water. The other is that you once you find the retarder/thinner ratio that works for you, you can have a premix bottle to work from. Try thinning with pure water first and see how that works for you. If you're still getting too much tip dry then try water with retarder. Pick a given quantity of water, like 1/2 or 1 ounce, and add 5 or 10 drops of retarder and try it out. Maybe someone has a specific ratio but I generally experiment myself to find what works for me.

Another option is to reduce the paint with Future and thin with water as necessary. Future is fairly thin but thicker than water. If you thin Acryll a lot with water the pigments fall out of suspension quickly and settle in the cup or bottle. So even though your paint's thin, pretty soon you're shooting almost pure pigment and getting clogs and tip dry. Using Future will help keep the pigment suspended while reducing the density of the paint so it requires less thinning to spray well. Again, just take a small bottle or cup and pour in some Future. Then add enough paint to get a good solid color and thin with a little water if you need it. Acryll thinner will work too. Acryll and Future mix readily with water. You can add retarder too if you want to try it.

Chances are that just switching to thinning with distilled water will work. If not, experiment with the Slo-Dri. General consensus is to turn down the pressure to the lowest point your brush will atomize paint properly. But sometimes, just sometimes, a slightly higher pressure will help.

Tony

Well, tonight I tried out the Slow-Dri and found it did help.  I thinned the MM Acryl about 60:40 paint to isopropyl alochol, and then added in a couple of drops of the Slow-Dri.  Tip dry was noticeably reduced and when it did happen it was easier to clear up, similar to what I experience when using Tamiya paint with Tamiya thinner.

Wingman -- it makes sense to me that thinning with distilled water, instead of rubbing alcohol, would further help reduce the tip dry (since water would not evaporate as quickly).  I will try that next.  Or, understanding that thinning with too much water could cause the pigments to fall out of suspension, perhaps I'll strike a compromise and thin with a 50/50 mixture of distilled water and rubbing alcohol (and add in a drop or two of the Slow-Dri if needed).

Update -- last night I tried using distilled water as thinner instead of isopropyl alcohol, and without any retarder.  Wow, what a difference as compared to the isopropyl w/o retarder.  Hardly any tip dry.  It would still happen, but only after a much more prolonged period.  In fact, if anything, the paint might take a little too long to try on the model this way.  Next I plan to try a 50/50 mixture of isopropyl and distilled water, and perhaps a drop of the Slo-Dri retarder for good measure.

Search some posts by Triarius on keywords "thinner model master acrylics". According to his profile he's a former paint technologist, and is one of the most knowledgeable persons I've read on this board when it comes to paint and paint chemistry. He's probably forgotten more about paint than I'll ever know.

I did a search just as you suggested, and found this quote by Triarius in a thread about Model Master Acrylics:

"I don't use Model Mucker ACK!ryl, period. I have enough frustration in my life, thank you."

I can't say I totally disagree.  Even though I have had success thinning and spraying MM Acryl with distilled water and retarder, when I go back to my Tamiya's I'm reminded of just how pleasant and troublefree airbrushing can be.

Kizzy

I did a search just as you suggested, and found this quote by Triarius in a thread about Model Master Acrylics:

"I don't use Model Mucker ACK!ryl, period. I have enough frustration in my life, thank you."

I can't say I totally disagree.  Even though I have had success thinning and spraying MM Acryl with distilled water and retarder, when I go back to my Tamiya's I'm reminded of just how pleasant and troublefree airbrushing can be.

 

Ha, yeah I found that quote too.

I've frequently had problems getting just the right thinning ratio with MM, or in some cases the paint was way too thin brand new out of the bottle for my preference. Tamiya is far easier to work with for airbrushing. Handbrushing  it takes a little more effort, but I've been handbrushing Tamiya for some time now after discovering that all it takes is a little retarder and some flow aid added to the mix, despite the many negative reports about it behaving badly when handbrushed. I just wish Tamiya would broaden their color range.

Agreed.  I'm only using MM in this case because Tamiya didn't have anything close to the color I wanted.

I use Windsor & Newton Flow Improver with the acrylics. It seems to help out with the ab clogging issue, specially when spraying  the cheaper craft paints. So far its worked really good. I just add a couple of drops.  

Not sure if it was just a fluke but I also found Liquitex's Airbrush medium to help a bit with tip dry and flow with MM acrylics.  The stuff is great!  I actually use craft paints more so than hobby brands and this stuff really made a difference...from good to great!  Unfortunately my local Michael's stopped carrying so I will need to find a new source.  :(

I believe Utrecht(smallish chain art supply store)carries it locally, perhaps an art supply shop near you may as well?  Or maybe Hobby Lobby?

Thanks for the tip re: the Liquitex Airbrush Medium.  I'm pretty sure my local Michael's carries it, saw it on the shelf next to the Slow-Dri.

Last night I sprayed the MM Acryl again, this time thinned at about 60:40 (paint:thinner) with an approx. 50/50 mixture of isopropyl alochol and distilled water.  No Slow-Dri retarder added.   The paint flowed pretty well and I got nice results, though predictably the tip dry would occur a little faster than when using only distilled water.  Still not much of a problem though.   Next time I'll probably just add a drop or two of Slow-Dri to the 50/50 alcohol/distilled water mixture and that should give me the result I'm looking for.

Another thing I found helps is to thin the paint in a small separate container before adding it to the color cup.  With my Tamiya acrylics that was never an issue, but I'm finding the MM Acryl really needs to be thinned separately ahead of time.  Kind of a drag, because there is some inevitable transfer loss when pouring from one container to the other, but it is easily worth the trouble it saves.

The alcohol makes it dry faster. Try using just the water and Liquidtex with the paint and see if that works out better..

Thought I'd post an update to let anyone who might be following this thread know what I'm finding to give the best results for airbrushing the MM Acryl.  To my surprise, I've discovered that once you learn how to prepare it properly the Acryl can give you an even smoother and nicer finish than the Tamiya acrylics, which I love.

OK, first, for thinner, I've settled on a 50/50 mixture of distilled water and 70% isopropyl alcohol.  I keep this pre-mixed in a small bottle so it's ready to go when I need it.

First, I give the Acryl a good stir in its bottle using my Badger paint mixer.  Then I mix it at about 60:40 paint to thinner.  As mentioned in an earlier post this should be done in a small separate container, prior to adding it to the airbrush color cup.  This way you ensure you are not introducing any unthinned paint into the feed tube that could clog the airbrush tip.

In addition, for approx. every 1 ml of PAINT that is in any given mixture, I add in one drop of the Liquitex Slow-Dri retarder.  I then stir the entire brew with a toothpick, THEN add it to the airbrush.  I spray at about 18 PSI through my Paasche H, and it works beautifully.  Overall I'd say the Tamiya (thinned with Tamiya thinner) is still easier to work with, but to my eye the results I'm getting from the MM may actually be better.

In any case, I hope the many others who are frustrated with airbrushing the MM Acryl will find this helpful.

Kizzy-thanks for testing & posting the results.  I'm looking forward to trying your formula.

I'm glad you found a mix that works for you. I don't understand adding alcohol to Acryll but if it works for you that's all that matters. You can get a very nice finish with it and it's pretty tough. Much harder than any enamel I've used and you can't wash it off with a little Windex.

Tony

MM Acrylics = hazing excercise to determine how much a person really likes airbrushing.

I really like airbrushing...