Posted 21 March 2012 - 09:46 AM
Posted 21 March 2012 - 10:20 AM
Posted 21 March 2012 - 11:21 AM
Posted 21 March 2012 - 02:28 PM
As Pete mentioned, resin is a different animal when it comes to customizing and given the cost of most resin bodies, I personally would be hesitant to chop one up. If you have confidence in your skills and have the extra money, then give it a try.
Best of luck!
Posted 21 March 2012 - 02:59 PM
Posted 22 March 2012 - 01:49 PM
Posted 29 November 2012 - 12:37 PM
Edited by Gramps2u, 29 November 2012 - 12:42 PM.
Posted 29 November 2012 - 05:08 PM
I've also found different primers will stick better, and it is not as easy as one best primer. What works well from one caster may not work as well as another brand on resin from another caster. In general though I have had pretty good luck with Krylon and Plascote grey or red/brown primers on resin, white not so much for some reason.
Posted 30 November 2012 - 06:10 AM
Thanks Aaron, I did do a tack coat as normal with the prime used the Testors laquer primer. It did etch in where I heavily sanded the 55 chevy suburban JF body shell & not where it was simply 'scuffed', Finding this out by restripping the primer once again
Posted 30 November 2012 - 06:54 AM
I know this IS an age old question "Perhaps" but I have a JF resin body, I have soaked it in Wesley's tire white, Dawn dish soap & a scrub brush hot rinse & last but not least the Yellow can of Easy Off oven cleaner and STILL The blasted primer wants to flake off even after scuffing the surface with a scotch brite pad. I have used 91% isopropyl alcohol too. The first primer job was lifted off by Chameleon paint remover thinking that should do the job as well, But no chance still slick as a slug. Other then backing over it with my Kenworth... What should my next step be to get primer to stick to it & not flake off? I have wondered if Dawn power dissolver would work & also would the krylon Fusion plastic primer be the answer? Guys, I am stumped & I have invested a lot of time on this project to simply just "trash it". ANY suggestions are welcome. Please help?!
Back when I was resin-casting, I used a clear adhesion-promoting surfacer from SEM, which I found in a local dealer for body shop projects. Automotive soft bumper covers are--guess what? Urethane resin. And this is what they use to get paint to stick to those covers, even with the flexing they sustain just in ordinary daily driving (not impacts). I tried it, and it works.
Posted 30 November 2012 - 06:55 AM
I've had issues with JF castings not wanting to hang onto primer before, as well, but I've found that if I wait about 48 hours and let it fully cure, it's no longer a problem. The primer will still want to flake off once it's dry to the touch, but after two days it's just fine. I've had that happen with other resins, too, but I've had it happen most frequently with the Flintstone castings.
Posted 30 November 2012 - 07:36 AM
Thanks Guys! I appreciate the answers. Modeled since 1967 but never with resins. Guess this "Old dawg" is gonna learn some new tricks! I am going to give the surfacer a try as well Thank ya much gents!
Posted 30 November 2012 - 08:11 AM
Posted 30 November 2012 - 10:46 AM
I whole heartedly agree with your statement, My question is after all of the proceedures I have used why is it still there? Has it impregnated into the resin? Thats some TOUGH mold release! Its amazing how "slick " it feels after all of this drama. I worked in composites for 13 years and never have I ever seen mold release this entense holy cow! Aint given up the ship yet.
Posted 30 November 2012 - 04:41 PM
If your primer adhered where it was heavily sanded and not where it was lightly sanded, this tells me you did not have all the release agent cleaned off the body, regardless of what you washed it with. There is no other explanation I can think of.
From my resin casting experience (I calculated from my production logs from AAM last winter--just shy of one million individual castings made from January 1989 to early 2000!): Polyurethane resin is impervious to the solvents in lacquers at least from spray painting, so the adhesion can be less than expected, and with enamels, very much the same thing.
This is why I suggested, above, getting some "adhesion promoting primer" (my experience was with the SEM product, which I used on all parts that were headed to the plater--as I was doing several quite delicate antique car bumpers (most notably the rear bumper for my '40 Ford Woodie Station Wagon transkit. I experienced a serious problem early on with the plating simply flaking off that bumper, due to it's delicate, very flexible nature, so I went looking, found the SEM adhesive clear primer.
I used that stuff on a run of bumpers, and when they came back I performed the following test: I simply took a bumper, twisted it almost to a pretzel (the type of resin I used was flexible enough to do that), and let it spring back into shape. Not only did the plating stay put, but when the bumper returned to its original, as-produced shape, there was NO evidence of any flaking--I actually built up the house display woodie with that bumper, and today, 18 years later, it still looks just as good as it did on the plating tree. So, I know that the stuff works. Any really good professional supply house for autobody supplies will have several different brands of this sort of primer.
Posted 01 December 2012 - 01:06 PM
Note to self buy some "adhesion promoting primer" Thank you Art! Being Saturday The true to fact automotive finish supply houses are closed for the week end. Come Monday I will try one shop "Car Color" (PPG products) if not there I will try the Dupont auto finish store. I called The local O Rielly auto jobber whom carries a small amount of auto finishes & to what I expected they didnt have a clue what it was I was asking for but did mention some adhesion promoting primer for ferrous metals & Non ferrous ( aluminum) . Going to invest in some . I have found the same effect with some of my own castings I have popped out recently. I am sold on your cure! Thanks again Neighbor!