After spraying a model with Dullcote, I find numerous small bits of dust and fine threads imbedded in the finish. I have to carefully remove them to get an acceptable finish. I was spraying at 15 psi with abot 1/3 dilution. The Dullcote was thoroughly stirred before hand and they does note appear to be anything floating around inside the bottle. This happen every time.
The previous time with this problem, I went out and bought a fresh bottle of Dullcote, thinking that the original bottle had deteriorated. I wanted to know where the imperfections are coming from.
I use a Badger screen filter on the inlet of my airbrush bottle cap. I wonder if that is fine enough? I hesitate to use a woman’s stocking as a filter in lacquer. I also wonder if I would have the same problem with “linting” with the clear acrylics: Polly Scale or the Badger equivalent?
I have sprayed colors before without any problems, although they were acrylics. Has anyone else run into this problem with Dullcote?
First thing I have to ask being an avid airbrush user, are you using some sort of spray booth or enclosure or are you spraying out in the open? It sounds like you may be picking up dust from the surrounding area.
You may also have a bad batch of product, check the code on the bottle and see if it’s the same as the first one you had the problem with. I once had a similar problem when spraying a clear coat on a motorcycle tank, Don’t ask me the chemical hows or whys but for some reason clear coats seem to be more troublesome then color coats. You may want to contact the manufacture and ask them if they have a spray data sheet on the product. Paint companies liek House of Kolor have such sheets for every product they sell whihc have spraying and mixing and storage instructions specific to that product.
I personally have never seen the need to shoot dull coat through an airbrush, I always use a rattle can and have had nothing but good results.
If you are spraying out in the open then I’d like to make a couple of suggestions:
Wet the ground down that you are standing on.
Don’t wear cotton. You can get an inexpensive jumpsuit at an auto paint store that will last a long time. Typically a Tyvek sort of material that doesn’t shed.
One thing not mentioned is the distance from which your spraying ,to far and paint can tend to dry somewhat before hitting the surface.I try to keep within 12" or a bit less to be sure the paint is wet when it hits the surface.
It’s been my experience when that happens, the dust and micro hairs were already on the car. You just can’t see that stuff too well. A layer of dullcoat on the other hand will really bring it out. So, when I have a car I’m about to paint, I’ll wash it in the sink under room temp running water. I’ll then dry it off with air from my compressor.
Sorry I wasn’t able to answer the questions earlier – brand new computer problems! Anyways, here goes: 1. I use a Paasche spray booth and the model and the airbrush were 6-8" in from the front. 2. I wash/washed this and other models in Dawn dish soap, thoroughly rinsing and air drying. I store the prepared model in a big ziplock bag until I’m ready to actually paint. 3. I have used the rattle-can of Dullcote for previous models (boxcars, etc.) to uneven results. I warm the can to room temperature, shake it well (30 seconds or so) and quickly spray one side of the model then the other, waiting between coats for it to dry. Even so, sometimes the finish is too thick for my tastes, sometimes just right. Seems to depend on the can. At almost $6 per can, the rattle can version is not a good deal. It doesn’t last long and gives inconsitent results. Airbrushed flat-coating is a lot easier to control. 4. I hadn’t though about the possibility of cotton fibers coming off my clothing. My usual dress is a t-shirt and shorts, both cotton. I am having difficulty accepting that the small fan motor in the Paasche spray hood (fractional horsepower less than 1/4 hp) has enough “pull” to attract free floating fibers from outside the hood. In my mind, the question about using acrylic flat coats still remains. Is it as good? Does it have less potential of attracting dust fibers because it doesnt’ have solvents in it? Also, about using women’s hosiery as a mesh filter while using solvent paints: will it work without dissolving the stocking?
Two suggestions come to mind A: don’t keep it in a zip lock bag as this will promote moisture build up aka condensation. It may not be noticeable to the naked eye but the solvents in the paint will find it immediately
B: I didn’t hear the mention of a tac rag being used before painting, this is an absolute must to remove any oils or dust particles that will attach themselves to the surface being painted.
C: Are you wearing rubber or latex gloves when you paint, not so much for keeping your hands clean but for keeping the oils form your hands coming in contact with the model. I have an 8x10 print out in my shop of a full hand print that showed up in a three stage flame paint job on a street rod from the owner of the car putting his unprotected hand on the car when I was mixing up the paint. It was a good thing he did it and not me, he’ll never make that mistake again.
I have to agree with you that the fan most likely does not have enough pulling power to pull fibers form your clothing but possibly if your in close contact with lets say your shirt it maybe static electrical transfer, I’ve actually seen that happen and couldn’t believe my eyes. but rather unlikely I suspect.
Thanks for the reply. I hadn’t realized the zip lock bag could be part of the problem. I do use latex gloves anytime I am handling a cleaned and prepped model, but I had not heard of a tack rag. What is it and where would I get such a thing? That may be my problem.