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Painting at Home with Summit Racing's Two Stage Urethane Paint System - Time To ShineFrom the February, 2012 issue of Street Rodder By Kev Elliott
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In the final installment of our “paint your car at home” series, we finally come to laying on the color. Body and paint prep is a long process when done correctly, and cutting corners will show in the final results. While by no means a fully inclusive series, hopefully you’ll have an idea of what goes into such a job, and feel encouraged to tackle painting your next project yourself. Summit Racing’s two-stage urethane basecoat/clearcoat system certainly makes things simpler, takes a lot of the mystery out of the process, and is formulated to meet National Rule VOC emissions standards. However, some areas, such as California, have more stringent regulations, for which low-VOC paint is available. Summit’s sales reps can help you with this. As with the primer stages, personal safety is paramount, though for topcoats, in addition to a good quality respirator, a spray suit is recommended (which features a hood), and though I didn’t use them, latex gloves too. The chemicals in paint can be absorbed through skin, so covering up isn’t just to prevent dust coming off your clothes while painting! For more details on the Summit paint system and related products, check out the company website, which is far more inclusive than the catalog. The paint guns, for example, don’t appear in print, but are listed online. Here’s where we left off last... Here’s where we left off last month, with the cab, doors, front fenders, and hood in black primer. The Indian Bronze Pearl I’d selected from Summit Racing’s paint color range requires a black basecoat. Some of their colors require a white base. Before we get into the nitty-gritty of painting, let’s mention a couple of other things. If you’re painting at home—or anywhere other than a dedicated paintbooth to be honest—preventing dust and debris from falling or being blown up onto wet paint is going to be tricky, but much of it can be eliminated by lining the garage with polythene sheets, Dexter-style, and wetting down the floor prior to painting. Don’t soak it, just wet the floor and brush it around and under the vehicle uniformly. It’ll stop the overspray sticking to the floor too! While painting, ensure you hold the air hose with your free hand, preventing the first 6 or 8 feet of hose from dragging on the wet floor, and to stop it hitting the lower portions of the bodywork as you work around the vehicle. Then there’s the subject of removing airborne overspray from the garage. Paint booths have very powerful fans to do this; I used a couple of $10 plastic box fans, one in the open doorway (there was absolutely no wind throughout this job or I’d have shut the door), and one in a window. I also have a small one built into the roof of the garage too. If you have close neighbors I’d recommend rigging up a water mist system directly in front of the fan, so the overspray is caught by the water and carried downward into a receptacle, not over the fence and onto a neighbor’s car or house windows. Just because it’s possible to paint at home doesn’t mean it’s not anti-social!  I thought I’d spotted all...  I thought I’d spotted all the pinholes in the body filler, but the black primer revealed a few more. This is the last chance you’ll get to remedy anything like this before topcoat! A little putty was applied before sanding with 400-grit paper, used wet.  With the masking removed,...  With the masking removed, you can see how the result is a “soft” edge rather than a hard line, which you’d get from simply using tape. The joint will now be imperceptible when the color is applied to the outside of the truck.  The entire vehicle was wet-flatted...  The entire vehicle was wet-flatted with 800-grit paper on a flexible block. Note: Do not add soap to the water. A sponge keeps the water flowing slowly to prevent the paper clogging and leaving scratch marks. Here I’m sanding the rear of the cab. I didn’t use a guidecoat as when the water is squeegee’d off, any non-sanded sections become obvious.  Almost ready to install the...  Almost ready to install the doors and start painting, but first all masking was removed and re-applied. As is illustrated by dragging my finger across the paper, there’s plenty of overspray dust from the primer stages, and fresh masking will eliminate any of this blowing up and landing in the color or clearcoats.  As I wanted to paint the truck...  As I wanted to paint the truck with the doors in place, it meant I had to paint the front of the doorjambs by the hinges, as well as the corresponding inner doorframe, as these sections would be unreachable with the doors on. While specialty masking foam is available to mask a “soft” edge, I’ve always used regular masking tape, folded over and taped down. Here’s how it’s applied.  With the outside of the cowl...  With the outside of the cowl masked off, I used a little spot-repair gun from Harbor Freight to apply basecoat to the jambs and inner doors.  With all masking removed and...  With all masking removed and re-applied, any remaining debris was blown off using an air line and wiping the bodywork by hand, before degreaser/surface wash was applied and wiped off. Note the polythene sheeting used to line the garage walls, as well as the roof. This not only reduces the chances of debris landing in the fresh paint, but also protects toolboxes and the general paraphernalia that collects in home garages, from overspray.  Once thoroughly degreased...  Once thoroughly degreased and blown clean again, a tack rag was used to remove any remaining debris. These sticky cloths pick up any dust or lint particles immediately prior to painting.  Finally we get to paint! And...  Finally we get to paint! And you thought it was simple huh? Here are the components that comprise Summit Racing’s two-stage basecoat/clearcoat system. The gallon cans at the right rear are the clearcoat, the gallon can at left rear is the clearcoat (and primer) reducer, the round gallon cans contain the basecoat color, while the smaller cans, from left to right, are 4 quarts of “warm” basecoat reducer, 4 quarts of “moderate” basecoat reducer (for use depending on temperature), and 3 quarts of clearcoat hardener/activator.  Summit Racing also supplied...  Summit Racing also supplied the HVLP (high volume, low pressure) guns. This kit is a DeVilbiss StartingLine HVLP gun kit comprising a primer gun and a paint gun, the latter with blue fittings. The paint gun comes with a 1.3mm fluid tip, while the primer gun has a 1.8mm tip. The kit also includes a gun cleaning brush set, wrench, and a regulator with gauge (not shown), all in a molded case.  Not wishing to encounter any...  Not wishing to encounter any problems with color variation between the three 1-gallon cans of basecoat (not that there should be, but you never know if all the cans were mixed from the same batch), I purchased a large bucket from my local auto paint supply house and mixed them together.  After donning a painter’s...  After donning a painter’s coverall, also from Summit, I used an old door from a previous project, which I’d previously primed black, to set up the new paint gun.  The basecoat was then decanted...  The basecoat was then decanted from the bucket using one of the smaller mixing cups supplied by Summit, into the largest. These are all marked with various mixing ratios, making it a snap to add the correct amount of reducer. The Summit basecoat is mixed 2:1 with reducer. Basecoat doesn’t need an activator. I mixed enough at a time to fill the spray gun twice, which was needed to apply a single coat to the truck.  Once happy with the gun, and...  Once happy with the gun, and after another pass with the tack rag and air gun, I was ready to apply the basecoat. Every painter has a preferred method, and as my truck has no roof, I started at one rear corner and worked my way around the truck, though the windshield frame was painted first, both inside and out, prior to each pass around the truck. This is the first pass, and as you can see, it’ll take several coats to cover the black base.  Seven coats later, allowing...  Seven coats later, allowing a five-minute flash time between coats, and an hour before applying the clearcoat, the job was complete. Summit recommends only two coats of clear, while I’m used to applying three. I followed the instructions though, as the clear flowed well and I was able to put on two fairly heavy coats. The clear is mixed 4:1:1, meaning four parts clear, one part activator, and one part reducer. Again, this is easy using the marks on the mixing cups. Once the overspray had cleared from the air, I shut the door and let the paint dry overnight. Incidentally, note how the overspray sticks to the water where the floor was wetted down around the truck. This means it won’t stick to the actual floor and can be swept up—something to bear in mind if you’re doing this job, like me, in your home garage.  No I hadn’t forgotten the...  No I hadn’t forgotten the hood. As I’d wanted to paint the top and sides of the cowl, which are under the hood, plus the fact that the hood overlaps the fenders by over an inch, I couldn’t paint the truck with the hood in place. I just had to remember how many color coats I’d applied to the body and repeat the same on the hood to achieve the same shade.  If you think lining the whole...  If you think lining the whole garage with polythene sheeting is unnecessary, take a look at how much crap landed on the top of the sheeting in the roof during this job! That’s without the extra dust that would be thrown around without the sheeting in place.  You’ll highly unlikely avoid...  You’ll highly unlikely avoid getting some “orange peel” in the clearcoat, as illustrated in the neon light’s reflection (arrow), but that is easily remedied during the color-sanding phase yet to come. The Bronze Pearl was more like Orange Metalflake once the clear was applied, and while initially a surprise, I’ve grown to like it a lot. This does underline the importance of test spraying a panel before tackling a whole car though, or at least seeing another car in the same shade, rather than trust a paint chip!  Flat horizontal areas will...  Flat horizontal areas will always attract debris falling into the wet paint, and this is the largest that befell the truck, right in the middle of the top of the right front fender! Notice in addition to the “flat” appearance of the paint, the fine dust particles that landed in the clear, probably overspray which wasn’t evacuated from the shop quickly enough, owing to my use of two cheapie fans rather than a high-speed industrial unit. Nonetheless, all this will “disappear” during color sanding.  Air Supply You won’t get very...  Air Supply You won’t get very far at all if you want to paint your car at home without an air compressor, and for this job Harbor Freight supplied one of their new 2hp, 29-gallon, 150-psi compressors. It delivers 5.9 cfm at 90 psi and 7.3 cfm at 40 psi, and features dual pressure gauges and a built-in quick coupler. It operates on 120 V and 15 amps, and while not huge, capably handled this paintjob, though admittedly it does struggle to keep up with a DA sander for long periods of time, but then a DA sander does require an awful lot of compressed air! Overall, this is an ideal compressor for home use, and is way more affordable than a two-stage compressor, capable of handling anything a hobbyist should require. It’s also easily portable, meaning it can be moved outside the garage during painting.  Color sanding is a bit of...  Color sanding is a bit of a misnomer when flatting clearcoat, as there’s no “color” sanded off, but the process involves wet sanding the topcoat with very fine paper to eliminate the orange peel and dust particles. Many proponents of the art will recommend starting with coarser grit, such as 800, then repeating the process with a fine grade such as 2,000. However, as this was my first experience with this paint, and the fact there were only two coats of clear applied (you DON’T want to sand through the clear!) I opted to use only a “superfine” 1,500 grit paper.  This is the ONLY time you...  This is the ONLY time you should add soap to the water when wet flatting paint. Again, a sponge will help keep your work “wet.” A flexible rubber block should be used to back the paper, though various other “blocks,” such as old radiator hoses or squeegees can be used to reach curved areas or sharp corners.  Once the surface is smooth,...  Once the surface is smooth, it’s time to break out the polishing mop and compound. Polishing compound comes in various grades, so start with a coarse grade and work up to a fine one, cleaning the mop head thoroughly between each. I used a Harbor Freight polisher here, though an adjustable speed version would have been preferable.  Admittedly photographed prior...  Admittedly photographed prior to color sanding and buffing, as I wanted to take the truck to a show, here’s the “finished” result. I blew some basecoat over the primer on the pickup bed, so the truck was almost one color, as that still required some repair and patch panels before paint. This is definitely a work in progress.  Constantly squeegee’ing away...  Constantly squeegee’ing away the water will enable you to check your progress. There’s plenty more to do here yet, as the low spots will attest. Flat the paint until it’s totally smooth.  After polishing, and following...  After polishing, and following up with a hand glaze, your paint should shine and reflect like this. There’s still some work to be done, as some micro scratches are still in evidence, but it’s nearly there. That neon light didn’t reflect like this before the color sanding began!
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