TUTORIALS - 3
HOW TO USE
GUNZE'S
MR.SURFACER
500 & 1000
by Gregg Cooper
There is no doubt that there are many different ways to put a finish coat of paint on a scale model. Likewise, there are many different ways to prepare a model for the finish coat. Every once in a while, there is a product that becomes available that changes everything we have learned about scale plastic modeling. Remember when you switched from tube glue to liquid cements? Or how about using cyanoacrylate “super” glue for the first time? Acrylic paints? Photo-etched metal parts? Gunze Sangyo’s Mr. Surfacer line of primers is another example of a good product that may become a permanent part of your modeling tool box. Mr. Surfacer is a viscous liquid primer that comes in several different grades, and can be applied in several different manners.
The idea of priming the model before painting is not a new idea of course, but the manner in which Mr. Surfacer behaves and the simplicity of using it will make you look closer at preparing the model for paint, and will certainly make things a whole lot easier.
Now, I am not a chemist, just a modeler in his mid-thirties that has been doing this kind of thing seriously for more than twenty years, but I will tell you that Mr. Surfacer will do some amazing things. It provides a ultra smooth finish perfect for normal paint application. It can be applied as a filler for surface imperfections, while at the same time NOT fill in panel line details. (!!!) It can be applied in such a way to FILL panel lines. It can be polished to a glass smooth finish. It can be an undercoat for metalized paint products. It sands to feathered perfection. It dries seemingly as hard as plastic, and it can be scribed. It can be airbrushed or brush applied, and even comes in a spray can.
Mr. Surfacer 1000 is the thinnest of the Mr. Surfacer line, and has become my choice for a primer coat before painting, Mr. Surfacer 500 is a thicker formula used as a liquid putty for filling unwanted panel lines and imperfections. I understand that there is a Mr. Surfacer 250 available, but I have never seen or used it. Mr. Surfacer is made in a formula for resin priming as well. I have never used the resin formula either, but I do use the 1000 and 500 grade regularly on resin with perfect results.
MR. SURFACER 500
Mr. Surfacer 500 is a very thick primer that is used mainly as a liquid putty. It can be thinned and airbrushed for some heavy duty surface filler work, like coating wood patterns for example. For the most part though, scale modelers will use a brush to apply it onto the offending seams and blemishes. MS 500 is able to fill small gaps, heavy scratches, small sink-holes or ejector pin marks, and most panel lines. It is a perfect substitute for filler putty in these circumstances. It cannot fill deep sink-holes or voids very efficiently due to the fact that it must be built-up in layers that can take a long time to dry, therefore a filler putty or CA glue would probably work better in these circumstances.
If all my efforts at pre-fitting, careful cementing, and assembly have resulted in a gap between two parts, like a separate or optional wing-tip for example, MS 500 can fix the problem.
This Tamiya 1/48 Mosquito wing has been
cemented
with liquid adhesive applied with a brush. Notice the gap
between the
Mosquito wing and the added wing-tip.
If this wing were painted now, the panel
line that forms the joint
between the two parts would look unsightly and
irregular on the
finished model, especially when treated with a wash.
After sanding with wet #600 grit
paper,
the seam is still ugly
Obviously, the joint requires attention, but we want to retain the panel line as well. One solution would be to fill the entire joint with a tube-type putty or CA adhesive, then re-scribe the panel line. Personally, I don’t have time to wait for the putty to dry, and I try not to scribe any panel lines unless I have to. Also, I don’t believe that it is a good idea to re-scribe directly over the filled panel line, because it is too easy for the scribing tool to wander off track due to the dissimilar consistency of the plastic and the fillers. MS 500 provides another option. Begin the repair by brushing on some MS 500 directly along the seam. Apply the liquid filler in a heavy, wet coat with a larger sized brush, a #1 or #2 for example. Usually, only one coat of MS 500 will be necessary.
One good heavy coat of Mr. Surfacer 500
should
fill the void, but leave the seam visible after drying.
At this point, there are a couple of different ways to continue. The tried and true method would be to wet sand the area, to remove the excess filler material. MS 500 if applied in a single heavy coat, will probably not fill the entire panel line. ( However, a second coat probably will.) If the area around the panel line is sanded until the excess filler disappears, it is very likely that the MS 500 has smoothed out the contours of the panel line, and filled any gapping at the same time. ( Don’t ask me how, it just works.)
Even though sanding will work, there is still a cleaner, neater, faster method that leaves the panel line looking even better.
If MS 500 is allowed to dry thoroughly, say an hour or so, it becomes quite hard, and perfectly suited for scribing if needed. However, before it reaches hardness, it is possible to remove the filler with ordinary isopropyl alcohol. A cotton tipped swab dipped in the alcohol, and wiped ACROSS the panel line, or perpendicular to it, will easily remove the excess filler.
The MS 500 was allowed to dry for ten minutes before
wiping the
joint with isopropyl alcohol. It is important to wipe perpendicular
to the panel line, or the filler in the line itself may be removed entirely.
The
idea is to remove the filler from the outside of the panel line,
and let the
filler even out the line from the inside.
The repaired seam.
As a bonus, the shape of the cotton tipped swab will allow it to protrude slightly down into the panel line, removing a little extra filler and leaving a depth similar to the surrounding scribing. That’s not all. This method of application and removal of filler allows the modeler to fill seams and panel lines without sanding off any raised details. The infamous underside wing joint on Tamiya’s Wildcat just became a cinch with this method. It is so easy you will be amazed the first time you try it.
The alcohol wipe method works extremely well with any joint or seam. If you desire the seam to be completely filled, apply two or more coats of MS 500 before wiping it down with alcohol.
Besides fixing joints and seams, MS 500 is exceptionally good at filling scratches, or mistakes made with a scribing tool. Simply brush on two or three heavy coats of MS 500 along the scratch, and let the filler dry thoroughly. Wet-sanding with 600 grit will quickly smooth over the scratch. The same method is used for any surface imperfection that must blend with the rest of the surface.
MR. SURFACER 1000
After the gluing and sanding and re-scribing, it is usually a good idea to use some method to diagnose your craftsmanship for any overlooked problems. The easiest way to check for flaws is to apply a coat of paint, usually referred to as primer, or surface prep. MS 1000 is a very good tool for checking flaws as well a base coat for finish paints. MS 1000 performs exceptionally well through an airbrush, and may also be brushed on, like MS 500, though it’s filling capabilities are not as good. I use it almost exclusively as a sprayed-on surface prep that doubles as a base coat for the finishing colors.
Some folks may shy away from adding any additional coats of paint to the model. MS 1000 is so thin and smooth that it makes everything look great, and does not fill panel lines to any degree of notability when used sparingly.
The Mosquito wing that was repaired with MS 500 is ready for a coat of MS 1000 to check and see if the joint looks ready for finish colors.
There have been many questions about thinning and cleaning up MS 1000. It is usually a safe bet that the thinner intended to be used by the manufacturer of a product is probably the right one to use. And, just as usual, the manufacturer’s thinner is probably VERY expensive. Well, in this case both situations are correct, which unfortunately does nothing for your wallet, since the medium-sized bottle of Mr. Color Thinner (110 ml ) retails for about $6.00 US currency. That’s a fortune in wasted thinner when it comes to cleaning the airbrush. I have to say for the record, that MS 1000 sprays absolutely beautifully with Mr. Color Thinner as a substrate.
Mr. Color Thinner contains a retarder that slows the drying time of the primer enough so that is sprays on nice and wet with no ugly over-spray building up in all the corners of the model. Even though Mr. Color Thinner contains a retarder, it still dries very fast. In most cases it is ready for handling and another coat of primer or even color application within 30 minutes. Within an hour it can be sanded and feathered perfectly.
Now to save your wallet from dehydration, here are a couple of tips. I still recommend using Mr. Color Thinner in the actual thinning and spraying of Mr. Surfacer 1000, however, there is an alternative that works very nearly as well, and is a whole lot cheaper by the gallon. Acrylic lacquer thinner manufactured for the automotive painting industry is a very good substitute for thinning and spraying MS 1000. There are many different brands, and types of thinners available in your local automotive paint store. To retain similar qualities with MS 1000, a retarded thinner should be chosen, one that is meant to be used in the temperature range of 60-80 deg. F, also referred to as “medium” fast thinner. My choice is PPG brand No. 876 acrylic lacquer thinner.
The main advantage to using this thinner is cost. At $20.00 dollars or so per gallon, it is not cheap to initially purchase, but it will last you for years. In comparison with MC Thinner, MS 1000 sprayed on with the PPG thinner seems to dry a little faster, but still goes on wet. It dries to a nice satin sheen, slightly less shiny than MC Thinner. I recommend both thinners, and leave it up to your wallet to decide.
As for cleaning up the mess, there is an even cheaper alternative. Go to your local home improvement store and buy a gallon of the cheapest generic lacquer thinner you can find. You should not pay more than $5.00 for the whole gallon. It works very good to clean the airbrush, and works very good at cleaning lots of other products used in this hobby.
Before applying any sprayed coatings, remember to wash the model with a mild detergent beforehand to remove any grease and oils that have gotten on the surface.
AN IMPORTANT SAFETY REMINDER: Wear a filtered breathing device while spray-painting. A “dust” filter mask, like one worn while cutting the grass, is not adequate protection, as it does not filter out fumes. Only a cartridge type respirator that covers both the nose and mouth provides adequate protection. Be sure to have the correct filter cartridges installed, and use a respirator that has been fitted to your size face. Never continue spraying if you can smell the paint while you are working as this implies a leak. And never continue spraying if dizziness or light-headedness occurs. Your local automotive paint dealer can help you with buying and fitting a respirator.
To apply MS 1000 with an airbrush, I recommend thinning it 1:1, or one equal part paint to one equal part thinner. Set your airbrush to a medium spray pattern, and apply at 30 PSI if possible.
The first step is the most important. MIST on the primer in a very quick, light coat, holding the airbrush approximately 3 to 4 inches from the model’s surface. The reason for a mist coat is to assure bonding of plastic and primer, and to provide a “tooth” for the next layer of primer. Allow the mist coat to dry for at least 5 minutes. The next application of MS 1000 will be a cover coat, and should be the only other coat necessary unless their are repairs to do. This time, hold the airbrush a little closer, about 2 inches away, and move it a little slower. The idea is to apply a wet coat of primer, laying it on nice and shiny.
It will dry to a nice satin finish soon, but it will not be smooth enough unless it is sprayed on wet. One trick that I use to ensure that there is no over-spray build up in any corners, is to shoot those areas first. Spray under the horizontal stabs, or around the bottom of a superstructure, anywhere there is a sharp angle that may trap overspray. This method assures that it will already be wet in those areas and melt any overspray that may gather there.
When the MS 1000 is dry, the model will have a satin sheen
that makes it very easy to see imperfections. Any fixes can be made easily at
this time( MS 500 comes to mind.) and spot painted with MS 1000 and an airbrush.
That’s it. All that’s left is to paint the model in your choice of finish and colors. Mr. Surfacer has become an essential part of my tool box. I will not build any model without using Mr. Surfacer as a primer or filler. Once you have tried it, I am sure that Mr. Surfacer will be in your tool box as well.