Hello Folks,
I have an XK 140 chassis that I have stripped of all parts and will be having it media blasted soon. I want to coat it with something soon after so it doesn’t flash rust, (Maine weather) It seems like, judging from the archives, many folks are happy with DP90 epoxy paint. My question is what do folks recommend for filing the rust pits? Also should that product be put on before or after the DP90. My thought is to blast it, then prime it, fill it, fix the rust holes then put a final coat of whatever black finish paint. Anyone have an opinion. It is appreciated.
Wes,
You may want to look at the epoxy primer. ( black) from southern polyurethanes. It is far superior to DP90, less expensive and can be directly applied any filling material you would like to use.
I would also recommend trying to coat the inside of the frame with a rust converter type coating such as POR 15. One gallon per frame leg does it nicely but it will be a mess. A rotational jig or any other way to rotate it is a must. Best of luck.
DP90 was a great product but is nla, superseded by DP90LF (ie. “Lead Free”) then in most jurisdictions by DP90LV (“Low Volatiles”).
You have a couple of options once the frame has been blasted clean. If it’s solid and requires no patches to be let in you can shoot it with a good quality epoxy primer, closely followed by a couple of wet coats of high build urethane primer. That will keep things stable till you can get around to addressing the pitting, which can be effectively covered up after sanding with a sprayable polyester, like Slick Sand, followed by final sanding, a coat of epoxy primer as a sealer and semigloss black chassis paint.
You should sound the frame with a small hammer once it’s blasted clean to determine if there are any thin areas that need addressing, but that takes time so exposes the frame to flash rusting. Flash rusting can be prevented for a few weeks by shooting the freshly blasted metal with WD40 but that will require doing a thorough solvent wash before you apply the epoxy primer to the repaired frame.
I dont think Id let WD-40 around anything I was planning to prime, much less paint. I guarantee you, that all that Jaguar did initially was spray it with some type of very cost conscious black enamel and called it good. I seriously doubt if they put any primer on it at all originally. Building paint/primer millage( thickness) will only bring about the potential for it later chipping with road use. Apply an aluminum composite filler such as ALL METAL to the deeper rust pits if you must. You will be surprised how well POR-15 lays out with you simply brushing it on- it will look like your sprayed it. If you decide to spray it, get a cheap paint gun you plan on throwing away. Prep it as they instruct, and it will be quite durable. DO NOT GET IT ON YOUR SKIN. No solvent that I know of will remove it from you.
Whatever floats your boat. I’ve used WD40 as a temporary rust inhibitor for years, allowing me to have completely stripped car bodies in my shop for months at a time without any rusting issues. For welding in patch panels it’s convenient if there’s no primer involved. Some restorers swear by weld-through primer but I don’t like the smoke it generates. I’ve never had subsequent adhesion issues but I’m religious about getting the metal ultra-clean before applying any coatings. For that process I use a spray bottle with final prep solvent to begin with, then a detergent wash, then spray on phosphoric acid followed by water rinse and thorough dry.
All Metal filler is an epoxy infused with aluminum particles. It will do the job, but for maximum chip resistance there are better epoxy options, as in those that are very tough but don’t get really hard.
There’s more than one way to skin a cat, as they say.
Hello Folks,
Many thanks for the input on paint. I contacted Southern Polyurethanes and talked with Logan. He recommended using two oats of their epoxy primer as soon as possible after media blasting. A gallon kit is about $200. Hopefully, that will do the trick.
Hey there, Wes. That will certainly keep flash rusting from happening. Epoxy primers have a limited open recoat window during which you can apply subsequent coats of more epoxy or other primers and colour coats without sanding, usually about a week. After that time you must sand the epoxy in order to get anything to stick reliably to it. This can be a lot of work.
