Paint runs when using an air brush

[cwclark]

Hi guys,
Don't know if it's the paint, the tape, or what, but i've been using an airbrush on some of my locomotives and am having trouble with Floquil's SP Scarlett ..i've mixed the paint in 5 different consistancies, tried different air brush needle settings, and different air pressures and the paint still runs under the tape...what am i doing wrong?...also..is masking tape the tape to use for masking the work?...Floquil's SP Dark Gray Lark paint goes on great, but when i switch to the Scarlett, it runs, won't cover well on the edges, seeps under the tape, and I have to put it on with a lot of passes with the airbrush before it starts to cover the work...I did primer the work before i started...Chuck

[Anonymous]

Chuck:
Do you work for Air Liquide in LaPort? If so do you know John Kupper in the Nederland office. He is a trouble-shooter for them and gets to LaPort quite often. He's a KCS guy with a nice layout, except he models those rectangular boxes with couplers called diesels.

Have a good day
Bob

[AntonioFP45]

CW,

I may not be much help, but the following helped me.

Couple of things.

(1) Re: Floquil.. some paints have a greater viscosity (fluid thickness) than others, reds are notorious for being a pain! Depending on your airbrush set up, you'll likely have to thin the Scarlett less than Floquil's standard recommendation.

(2) What type of tape are you using? Stay away from the cheaper brands. High end tapes from 3M are your best bet. It's worth the extra couple of dollars. I use the 3/4" standard tape as well as the 3M fine line tapes. The fine lines tapes are blue. Some modelers use the "Drafting Tape" that's favored by architects, also available by 3M.

(3) Before painting I make "double sure" that surfaces are very clean. Even on new undecorated shells.

When starting years back, I would wash and clean a model, only to turn around and forget that my hands had started to sweat or I touched an item, table, person that had some oil residue on it. Humans are natural carriers of silicone. Any traces of oil or silicone on a surface will be a spot where paint runs or "fisheyes" will appear. Fisheyes look like tiny holes in the paint. These are actually spots where the paint won't stick, so it will "flow around" the oil or silicone.

Again, even though the paint chemical binders are usually the same within a brand line, red pigments are notorious for not adhering to contaminated surfaces.

Don't feel bad as quite a few people, me too, have had similar problems.

Let us know of your progress! [;)]

[CraigN]

I always paint in light coats, I paint a coat let it dry and then apply another coat ect. ect.
By doing it slowly, it allows the paint to dry and seal the edges of the masking tape. It may take me a long time to paint, but the end results are well worth it!
Also make sure you press the edges of the masking tape as you apply it, you need a good seal to prevent the paint from bleeding underneath it.

[Virginian]

Use 3M tape. Spray the first couple of light coats fairly dry. Practice on something other than your engine. Let dry between coats.

[cwclark]

QUOTE: Originally posted by TEFFY

Chuck:
Do you work for Air Liquide in LaPort? If so do you know John Kupper in the Nederland office. He is a trouble-shooter for them and gets to LaPort quite often. He's a KCS guy with a nice layout, except he models those rectangular boxes with couplers called diesels.

Have a good day
Bob

Bob,
I have heard the name but personally don't know him...I work at the big Bayport plant just down the road from the La Porte plant..we have one other modeler out here, a guy named James Smith ..he does N scale and he may be in the SJMRR club...we also used to have an instrument tech out here that did HO but he's not with the company anymore...When and where does the SJMRRC meet?....and what's wrong with diesels?at least they're a lot better looking with the nice paint schemes than those old chok'in smok'in dirty, grimy, steamers!...[:D] Chuck

[cwclark]

thanks for the input guys...I think i'm going to have to put the paint on in thin layers...i'm trying to cover it all in one painting session and in the process, i'm applying too much paint so that it's running under the tape...Chuck

[Anonymous]

I'll second AntonioFP45 on the good quality tape. Try an art supply store and spend the extra money on the drafting tape. Its usually white. Seals real good at the edges unlike the blue painters tape at Home Depot.

[Anonymous]

Two ideas that have helped me...

1) Always cut a new edge on your tape - don't peel it off the roll and expect the edge to seal. Cut off a few millimetres to get a clean edge.

2) Seal your tape to the work by either spraying with the underlying colour, or dullcoat. If there is any bleed under the edge, it will match, and it will keep the red out.

Hope that helps.

Andrew