As chrome can't easily be sanded, you HAVE to use an etch primer to connect the paint to the substrate. As well, over the years I've found Tremclad brand paints binds extremely well to odd materials, so that's what I'll be using here - just for that extra bit of bite I might get.
Before starting the masking process, I wiped every piece down with a wax and grease remover. I have some in a gallon bulk container from Pro Form, but I also like Eastwood's PRE in an aerosol with straw sprayer. It's easy to apply directly to the pieces and then wipe off. Just make sure it goees on wet and you wipe it off while still wet. That's how it removes contaminants.
First task is masking the parts that you don't want painted. I'm using "Fine Line" tape from 3M, which is a vinyl tape that stretches easily around curves and bends, as well as standard 3M 1/4" as well as 1" and 1 1/2" masking tapes.
A quick bit about masking tape: there is really no substitute for 3M brand masking tape in the auto body business. I've been doing this for over 35 years and in that time have tried several brands of tape and can honestly say both the glue and the paper is better with the 3M brand. Other brands have glue that comes off on your work, get gooey when exposed to moisture or heat, dry up if left out too long and the paper used is often too thin. As well, regarding shelf life, the entire roll can deteriorate very quickly. Many shops try to cut a few corners and try other brands, but the best shops always go back to 3M. It's just a product you don't need to cut corners on - OK, you actually cut a LOT of corners on masking tape (!), so you want the best there is. End Rant.
Once everything is all masked up, I'll clean it again with a Wax and Grease remover. There's no telling how many contaminants come off your hands - like skin oils, whatever else you've touched - and that's exactly what causes "fish-eyes" (pinholes in primer or paint) and adhesion issues. As well, there are airborne particulates that settle on your parts as you get ready to paint, which you want to minimize by cleaning again just before applying your primer. On alrger jobs, professionals also use a "Final Wipe" to clean the panels between primer and paint and even between base and clear coats.
Two to three coats of Self-Etching primer were applied. After sufficient dry times, but still within the "re-coat window", you can apply the next coat. The re-coat window is a term that describes the time where the previous product or coat is dry enough that the solvents have sufficently flashed off whereby another coat won't cause a run or sag but still soon enough whereby the chemical bonds can still be`adhered to by the next product or coat. Each product will have this information on the can - or in it's MSDS sheets. It is a critical time period and easy to manage when known. If the re-coat window is exceeded, the previous coat will require mechanical abrasion (sanding) to allow adhesion of the next coat.
After applying the paint (one medium and 2 wet coats of the Tremclad Red), I threw together an impromptu bake oven. It bears a mention here that it's not the equipment you have, but the processes you adhere to. Since we know primer and paint adhere, flow and set-up better at warmer temperatures, it's prudent to keep the parts warm - no matter how you get them there! Normally, I would be using my parts painting booth, but I had dismantled it after the lion share of the parts had been painted to make more room for parts re-assembly!
NExt, the process is repeated, though on a much smaller scale. I need to reverse-mask the Chevy Bow-tie's in the centre of the hood and horn pieces to spray them black. Stay tuned for that process and a photo of the final product - they'll look GREAT!
Now..... back to the gas tank. As anyone who has tackled a restorations knows, there can be a lot of prep that goes into the re-installation of some parts. After the "fun" I had drilling out the three broken bolts for the tank straps, I spent time connecting the electrical and gas lines that reside behind the tank and connect the sending unit.
A key side note: Grounds are absolutely CRITICAL and will haunt you forever if you don't give them proper attention. Make sure - whether it's an engine to body ground, a signal light, or this gas sender ground wire - you scrape away the paint that the ground wire attaches to. It's NEVER enough to assume a screw will be sufficient ground - because 12 out of 9 times it WON'T be....and you'll be searching forever trying to figure out why you gas gauge is bouncing around! There's many a cautionary tale of guys and shops replacing all kinds of equipment trying to get things working when it was just a loose or impoperly set-up ground path.
Of course the next thing you'll be thinking is: "What about RUST?" This is where you should use some grease (di-electric grease is good) to protect the the area from the elements - AFTER the connection is tight.
Once all the connections are made, I used some tape to keep the wires within reach after the tank gets installed.
As well, the tank straps where attached on the back side with new hardware:
Next up, yesterdays news: Remember the cowl seal and the crappy METAL clips that came from the "repop" (re-manufacturered parts supply) company? As I wrote yesterday, I decided the metal ones (after breaking a couple!) could scratch the paint causing rsut, or just rust themselves. So I went to my local autobody supply store and found a couple different PLASTIC clips to try.
Be careful where you go though and check pricing on these small items! A lot of places price clips and other small hardware pieces at ridiculous "Insurance Company" prices. It's an auto-repair industry secret (or was!) that nuts, bolts, clips and such are marked up 300%-500%, because insurance company's pay for them and rarely argue. In this case, the EXACT same clip at one supply house was $9.56 retail ($6.56 my cost). At another place that same clip was $4.70 retail ($2.35 my price). Still pricey for a little piece of plastic, but far less than the first place!
Unfortunately, the wide-topped clip was too big for the hole in the cab. It would have been preferable to hold more of the surface area of the rubber seal, but I ended up using the smaller clip. I justified the choice with the realization that the seal would not be subject to any shearing forces, just the hood setting down on it and then lifting straight off. I think of stuff like that....
Lastly, I applied the sealer to the gas tank. During the day I rinsed it out again with water about 4 or 5 more times, then thoroughly dried it with mechanics paper towels (attached to a grab-it tool) and also a heat-gun stuck into the sending unit hole. Once very dry, I rinsed it with white gas (Naptha, or cooking stove fuel), then allowed that to dry again.
Finally, I was ready for the sealer. There are several manufacturers to choose from and for the Challenger tank, I used Eastwood's sealer, which worked VERY well and dried to a white rubbery film. This time though, I had a can of Steven's that I purchased a while back. It came highly recommended from the Model T and A (I love saying that!) community. It looked like honey, so I'm guessing it will dry clear. Tomorrow we'll know!
Regardless of which one you use, follow the directions, which include pouring in the sealer, taping shut all the holes (filler neck, air tubes, sending unit hole...), then slowly turning the tank in ever direction and holding it in each position for a minute or so. This allows the sealer to evenly coat the tanks insides. Once exposed to air, the sealer will dry to a semi-rigid film, impervious to fuel and water and sealing in any rust or scale that are left on the tank walls. These products will also seal small pin-holes, but of course it's advisable to repair those before getting to this stage. In this case the tank had held up well, it was just full of rust, scale and old, foul gas!
I removed the tank plug and set it up so that any excess sealer drained out from this opening. Don't use other openings, as the sealer will obscure them again. With the drain hole, you can always open it up again after the sealer has cured, with a piece of wire, pipe cleaner, or what have you. The can says a minimim of 24 hours is required before adding gas - but it'd be best to err on the side of caution. Double it in warm weather and triple it if cooler. I'll be giving it much longer!
Don't forget to check out the website at www.E-tekRestorations.com
Special thanks to www.Eastwood.com and www.CarCraft.com!