Jump to content

bobbenko

IPMS/USA Member
  • Content Count

    6
  • Joined

  • Last visited

Community Reputation

0 Neutral

About bobbenko

  • Rank
    SnapTite
  • Birthday 02/22/1952

Profile Information

  • FirstName
    Robert
  • LastName
    Benko
  • IPMS Number
    31284
  • Local Chapter
    Centennial IPMS
  • City
    Pueblo
  • State
    Colorado
  • Gender
    Male
  • Location
    Pueblo, CO
  • Interests
    Sailing Ships, Modern US Aircraft and Armor, WWI Aircraft, Formula I Racing, Medieval Figures.
  1. As a retired Chemical Engineer, I felt compelled to add some clarification to PeteJ's good explanation. The "sweet" smell of the acrylics is more likely to be from "glycols" that are added to the paint to get the paint to flow smoothly. Other glycols that you know are automotive antifreeze (ethylene glycol). The acrylics that PeteJ mentioned are not pigments but the binders in acrylic paint. They are long spaghetti-like molecules that glue the paint pigments to the surface that you are painting. Acrylic clear coat is just acrylic binder and solvent; no pigments. The pigments that PeteJ mention come in two categorizes: Inorganic and Organic. The inorganic pigments are, as PeteJ says, natural minerals. Ground up dirt if you will. Examples are Titanium White, Yellow Ochre Ultra Marine Blue. The organic pigments are usually man made chemicals or molecules that were originally extracted from crude oil or coal tar. Some of these were first discovered by German Chemists in the late 1800's. Examples are: Phthalo Blue, Phthalo Green, Napthol Red. BoB
  2. bobbenko

    CSS Alabama

    Cottage Industries Models (www.cottageindustrymodels.com) makes gun upgrade kits out of resin and white metal for both the CSS Alabama and the USS Kearsarge Revell Kits. Two sets are available for the USS Kearsarge: Civil war version and post war version. Quoting from their web site the USS Kearsarge out of the box is in post war appearance. I have these gun sets. They make a lovely addition to either kit. I can strongly recommend them. Blue Jacket Shipcrafters (www.bluejacketinc.com) now offers resin kits of both of these ships in 1/8" = 1' scale (1/96). There was an announcement here on the IPMSUSA forum about a year ago. The Finescale Modeler magazine forum is a very good source for information on sailing and steamship kits and their history. The section on ships is one of the best around for this type of modeling. Searching the ship section for CSS Alabama and /or USS Kearsarge brings up many topics about these Revell kits including building details and kit accuracy. BoB
  3. "Retarder" slows or retards the time it take for the paint to dry. Said looking at it from the other direction: the paint stays wet longer. "Flow Improver" reduces the surface tension and to some extent the viscosity of the paint. The paint is less likely to "bead up" so it "flows" better. Back in the day, the drop of dish soap that you added to a bottle of Poly S paint was a flow improver. "Thinner" is mostly the liquid in which the acrylic paint binder molecules are suspended. For many acrylic paints, the liquid is simply water. But others, like Tamiya, use all sorts of goodies (alcohols, ethers, glycols, etc. read the ingredients label for fun). Most paint manufacturers also add some retarder and flow improver to their thinner. Some acrylic paint formulations can adversely react to another labels' thinner/retarder/flow improver. The paint can get lumpy or stringy. That is the result of that adverse reaction. So best to use the manufacturers' own products unless you have tested to make sure nothing happens. Better to have stringy paint in the test cup rather than in the airbrush or on the model. Of course, you can always add to much of a good thing. Too much retarder prevents the paint from ever drying. Too much flow improver or thinner can cause adhesion problems. Best to follow the paint's directions. But in general, one or two drops of retarder or flow improver to your pot of paint is usually enough. Adding up to 25% by volume of thinner is no problem; 25%-50% can get dicey with adhesion; more than 50% you risk serious adhesion problems. You have been warned. Now, if you need to thin more than 50%, consider using one of the paints' "mediums" (which is basically just clear acrylic paint; Future Floor Wax/Pledge can be considered a sort of universal acrylic paint medium). But that is another discussion.
  4. There are three main problems that can result in peeling acrylic paint. 1. The surface is dirty. Usually the dirt is oil of some sort from skin, mold release, etc. Just wash the surface with soap and water then keep it clean and dry before painting 2. The surface is too glossy. Acrylic paint need some roughness or tooth on the surface to grab on to. Buffing or sanding the surface to remove any gloss takes care of this one. 3. The acrylic paint is over thinned. Acrylic paint is made up of an acrylic polymer emulsion binder, paint pigment, a solvent (usually water, sometimes alcohol), and a small amount of conditioning chemicals (flow improver that makes the paint mixture less viscous, retarder that slows the drying, a fungicide to keep the paint from growing mold, a biocide, thickener, defoamer, etc.). If too much thinner (water, alcohol) is added, the acrylic polymer becomes too dispersed on the surface; there is not enough acrylic polymer threads interweaving among themselves to properly grip the tooth of the surface. Using fabric as an example, good polymer dispersion looks like felt; poor dispersion looks like cheese cloth. Most acrylic paints should be thinned no more than 25% but usually 40-45% is still OK. I have found adhesion problems at 50%. To make a thinner, more "transparent" paint mix without over thinning, stir in more pure acrylic binder by adding to the mix the paint's gloss clear (Future floor wax also is a good cheap "pure acrylic binder"). Acrylic paint gloss coat is just acrylic paint without the pigment. My current cheap airbrush paint mix is: Craft paint (like Creamcoat or Anita's), Future Floor Wax, and 70% rubbing alcohol mixed about 50:45:5. My quick mix procedure is to take 1 part paint, add 1 part Future and then add just enough rubbing alcohol to get my ideal airbrushing thickness. Peeling paint could also result from over adding paint flow improver and/or retarder. These are available at art stores in the acrylic artist's paint section. I have experienced this problem myself but probably is not the issue here. I have airbrushed my cheap airbrush paint mix onto the hulls of my plastic sailing ships then masked with blue painters tape and Tamiya masking tape and have not had paint peel. I have also been able to feather sand the paint edges to make repairs without peeling. I rarely prime plastic but do prime photo etch and resin. Ultimately, the paint may need to be stripped because the remaining paint probably has the same issues.
  5. My memory was jogged by this thread. I found in my decal stash 2 sets of marking for Ju-188's from Third Group (copyrighted in 2000/2001, the company has been out of buisnes for many years) in 1/48 scale. 1) 48-058 has 3 Ju-188's, 2 E's and 1 A, Milch's Transport, KG 26 & KG 200. 2) 48-061 also has 3 Ju-188's, 2 A-2's and 1 D-1, KG 6, 26 & Aufkl.Gr.(f)33. The marking are the usual gray, white and black letters and crosses. 48-061 does have yellow 'G's'. Probably nothing that couldn't be found on other available sheets. Thought you might like to know. BoB
  6. I think it is 'Seminar Plastic Model Co.,Ltd' from Korea. I have a 1/35 UH-1B Iroquois with the exact same logo. The instructions in that kit say Seminar. My brother reads a little Korean and he says that the Korean writing (letters)phonetically sound out 'Seminar'. BoB Benko
×
×
  • Create New...