guys, i am in the process of filling and smoothing my vent cowl on my 1957 3100. mostly because it leaks a lot when it rains, and i also like the smoothed out look. i am going to paint it myself and need some tips. i want to use the base coat / clear coat process. i have painted a few bike like this for my nephew a few years back, but all i did was prime, paint, then clear, no sanding in between, which is what i want to do on my cowl, making it as smooth a finish as i can. so my questions are, 1- how long between prime, paint and clear coat before i can wet sand on each step ? 2- will waiting a day after each be ok to wet sand on it then ? 3- what grits should i use to wet sand ? i have it just about ready to shoot, but still need to buy the primer, paint and clear. so far i have it sanded using 150, 200, wet 600, wet 1500, and finally wet 2000. never realized bondo could get that smooth. slick as glass, and that is the finish i am wanting when completed. any and all help would be greatly appreciated. oh yea, do you agree that the name for the color of my truck is "tartan blue" ? i was told its a 1958 hue... thanks much. leonard
First, You'll need the filler to have some tooth to it, like 80g-120g Primer WILL NOT stick to anything that is that fine grit...It requires some scratches to grab onto...Primer will peel off if painted over 2000G! Most paint companies have pretty clear directions as to what grit to use, and how long to wait between coats...seems like every company has it's own system, requiring it's own set of steps...Good luck! EW
Best sand that bondo with 220 and prime it. Too smooth and you leave no tooth for the primer to latch on to. Wet sand the primer to 400 or 600. Spray the base, and only sand for nibs after the 2nd to last base coat. Clear coat, wet sand and polish as needed.
WOW. good thing i asked some questions huh ? stupid me would have primed right over the 2000 grit sanded surface.... i will rough it up before i prime it... can i use the 400-600 wet sand on the base coat, before clearing ? and what is the grit i should start out with and ending with when i go to wet sand the clear ? thanks much. leonard
Leonard, you might wanna lay a drop light on the bondo for a few minutes or heat it up with a heat gun.....you really shouldn't wet sand filler because it will absorb moisture! Dry it out good before you prime it
perfect, thanks.... it will be a week or so before i get around to priming it, but i will make sure its out in the sun also beforehand.. leonard
Leonard, wish I could help with tips, but I'm no painter. I'd like to see pics of how you went about filling the panel though. This is something I've had in mind as well.
terd, i bought a vent cowl off e-bay for 30 dollars and was going to cut out the vents and fill in with metal, then some thin bondo, but since its a compound curve it would have been too hard for me to make..... so i got some fiberglass resin, taped the top side, and flipped it over and dabbed the resin into the vents from the underside... when hard, i peeled the tape from the top, and then bondo'd and sanded to get the finish i wanted... hope this helps.. leonard
Hey Leonard, I don't wanna muddy up the pond with your wanting to smooth over your cowl & get some colour on it, but I think the day will come when you'll regret your choice of methods! Resin, be it polyester or epoxy and poured into a gap will over time crack. Too, that area of a vehicle gets alot of heat soak given it's over the engine especially after the engine is switched off. Intense heat causes sheetmetal to expand at a rate different from the resin you've dribbled around the cowl vent opening, and yep, you guessed it will also lead to more cracking. I'd suggest you grind out the putty & resin, clean the flange all around the cowl vent door, and weld in the door to the cowl panel. A piece of gas welding rod the thickness of the gap between the door and the flange will make for a clean fit up between the two, and make for an almost no filler needed repair. Do a good job of welding the door in, with many widely spaced tacks with plenty of cooling off periods between tacks/beads, and only a slime coat of plastic filler be necessary. Leave the resin to the hot tub and Plasticcar guys! " Life is not a Disney movie "
First probably get a book and not just use advice on a message board. I say that because the book will help out with pictures and other info and then you'll have a quick reference when you need it. Make sure to do your bodywork properly. make sure it's dry and its clean before you prime. Use good primers that have hardeners and follow all instructions. When you get to the paint just keep it clean in between your application of coats of paint and clear to keep the dust out of it. Use good quality tack clothes. If you are using metallic paint, do not sand it down after it has been painted before you clear it because it will mess up the metallic in the paint. You can wet sand most of the little nibs out after it has been clear coated and has dried properly. Wet sand with 1500 to 2000 paper.
thanks for the info guys.... since i got an extra vent cowl off e-bay, i will see how long it lasts the way i did it for now. i will save the one thats still on the truck now, but i do like the idea of just closing off the vents at the kick panel.. thanks leonard
If it were me I'd scrap the resin job and weld everything up properly. You are gonna put a lot of time, money and effort into painting and buffing only to have the resin crack in the near future ruining all your work. There is an old saying that a paint job is only as good as the body prep work. Also if you have never sanded and buffed out clear coat I'd maybe practice with your buffing technique on a test panel or something cause it can be real easy to burn the paint if you aren't careful. The simple rule for wet sand and buff is coarser grit=less sanding more buffing, finer grit=more sanding less buffing. Pick your poison!
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