daem0n

Ok, a couple questions for all you DIY's out there. I'm interested in putting over-fender flares onto the rear of the car. I heard the best way to do this is to rivet it to the vehicle (it's fiberglass fenders) and then mold it all together. What I'm wondering is, what's the best way to do this without the most damage to the vehicle? Like, are rivets safe for attachment? I'd rather have durability I guess. Also, how do you mold a part like that to the car? Would you just use bondo to fill it all together? And if so, how would the bonding agent react as in stress? Wouldn't the constant hitting of bumps and stuff on the road (while driving) end-up stressing the attachment points of the fender? (especially where it's molded)... And, one last thing - how would you go about getting the paint on this part to match the rest of the car? Would you scuff-up a bit of the car leading to the part to "better" match the paint to the rest of the body? I'm not too worried about the painting as I'll leave that to someone else. Anyhow, any reply no matter how intelligible you are on the subject would be appreciated Thanks, -Joe

Spawn VII

interesting topic... im looking into some over-fenders for my TII too, and this would help a lot on how to get that thing on

daem0n

Just an update to this, I found some info that bondo won't bond the two parts together (the car and the fender) very well because of them being made out of different materials. Fiberglass and metal have different expanding/retracting temperatures which can cause the bondo to crack where it was holding the fender to the car. If this is the case, is there not a material that would be better suited for the job? There has to be a solution out there...

unvmyrx7

iTrader: (14)

i worked in a body shop for over 3 years, here is what u need to do.

u can get a 2 part expoxy to bond the fiberglass flares to the quarter panels or fenders if u don't want to drill holes and rivet them to the car. duramix makes alot of epoxies for this. car makers have been bonding door skins and quarter panels, instead of spot welding them for years. you would have to sand the paint down to the metal to get a good bond.

you can mold the fiberglass flares to the metal, by using fiberglass reinforced filler. they have names like gorilla hair, bondo also makes two type of this filler. its very hard to crack and it doesn't shrink. its not as smooth as regular body filler, more like chopped fiberglass.

after moulding this to the car, use a good urathane primer, not those cheap lacquer primers.
wet sand the primer with 400 grit, then 600 grit, then 1500 grit or scuff the clearcoat on the entire quarter panel or fender. blend the new paint to the old , and clear the entire fender or quarter panel. good luck

CCarlisi

daemOn:

This is the hangup that I and many other people have re fender addons. The consensus seems to be that bonding will hold, but will not stand up well to abuse. The most durable way to do it would probably be to just riviot it without bonding it. Personally I'm not crazy about how this looks, but it will not detract from its function. Also, I don't like the idea of cutting away the stock fender lips :p -not doing that will make the addons pointless.

rx7speed811

bonding/molding might hold fine for a year or two, but if the temperature extremes between seasons in ottowa are very contrasting, you might start to see cracks in the filler. the fiberglass from the flares, the metal from your fenders, and the fiberglass fiber fillers and urethane primer all expand and contrast at different rates when the temperature changes, so unless you have the most flexible paint in the world, you will start to see cracks.

unvmyrx7

iTrader: (14)

i dont know about the seasons in ottowa, but here in n.y. we have been molding kits on cars for years and don't have any problems with cracking. we even mold fiber glass to flexible bumpers. the veilside rear add on are molded to metal and the rear bumper on tony's car from t & r racing the only time these developed cracks is when they got hit. my cousin was the first to cut a turbo II hood and mold it to his first gen hood. the only time the fiberglass filler cracked was when he crashed the car

daem0n

Thanks for the replies guys. unvmyrx7, I'm glad you haven't had any problems with the method that you're mentioning because it's giving me some hope for my idea. I mean worst comes to worst I could just leave the rivets visible, but I think that would look horrible just because on top of having the rivets showing you have a piece of fiberglass just hanging off your car. But then again, if it's for function you can do that. I'm hoping to get both function and "look" out of this. That gorilla hair bond stuff that you were mentioning sounds ok. I don't really care if it's rough, as long as I can fix it up in the end. The climate in NY is probably the same here...I never take my car out in winter anyway. Although, it's not kept in a heated garage either. So far unvmyrx7's idea sounds best to me...even if it cracks after 3 years or so, I don't mind maintaning it. Does anyone else have any suggestions?

Rob XX 7

iTrader: (8)

my suggestion would be to leave the job to a pro, putting panels on is one thing, but doing the bodywork to make them look like part of the car is the hard part, harder then painting.

And you should be set on painting the whole fender, and most of the quarter panel or at least until a good break off point, you cant just paint a inch or 2 away from where you did the work. Most people do this kind of thing when they are getting the whole car painted.

If you use rivets you can always fill over the rivet holes, I would say to use a panel bonding adhesive between them, then you can probably take the rivets off and fill the old holes in. They are glueing quarter panels together, so I cant see any reason for your fender flares to not hold up. But for a "just in case" I would leave a couple of rivets in, just fill in over them.
Again let me say that GOOD bodywork is hard to do, anyone can make a wavy nasty mess. Any bonding should also be done to bare metal that has been grinded, not a painted surface.

daem0n

Hey Rob, thanks for the input - I guess I will leave the rear attachment to an expert. I don't think I want to be riveting the car myself anyway :P I'll probably just end-up painting the quarter panel though because the paint isn't that old.

Rob XX 7

iTrader: (8)

when I say paint, I should say clear coat, usually they will blend the color into the panel, then clear the whole panel. Sometimes you have to do the adjoining panels to look right.

LT1-7

This is what I did. I drilled holes in the body piece to be molded. Added a countersink. Screwed the body piece on. Add fiberglass on top of where the body piece meets with the body, 2 layers will do. Sand down to a somewhat smooth finish. Add filler on top. Sand smooth for primering. Your whole car will have to be painted to have a real match. It is way to hard to paint just one area to match the whole car. I did this to my rear bumper and here is a story that let me know it was a hella strong hold

I jacked up my car one day to install my new wheels. Everything went well but when I went to drop the car down, I noticed it didn't go down far enough, I still had about 6" between my tire and wheel well. Well turns out my rear bumper was on a bottle of fiberglass resin. To have the rear bumper hold up at least 1000lbs of the car is a strong hold. Not only did it hold the car up, it didn't even crack the fiberglass at all. So as far as strength, my way will hold without a doubt. As far as temp? I haven't tested that to the xtreme yet

daem0n

hahahaha - nice story RedTT. Sounds like a good method too. So, do you think when someone gets a body kit added onto their car, do they always repaint the whole car? I thought most paint shops has advanced enough technology to match a colour even if it's been a bit faded (not that it has to my knowledge). And, if you had to repaint a whole car, is there a way to do an overspray by maybe getting rid of the clear-coat somehow? I may be an artist, but I've never painted a car :-P

Rob XX 7

iTrader: (8)

you can paint your car and save some of the paint thats left over, and lets say 6 months later you hit the fender and repaint only the fender, there is a good chance it wont match. You can paint a whole car and lets say you have the fuel door or the door handles sitting flat and not in its proper mounting position, there is a good chance the paint wont match the rest of the car. This is mostly for mettalics by the way.

unvmyrx7

iTrader: (14)

this is very true, also the vintage red and competition yellow mica color is a 3 stage painting process. the vr base coat is orange(ish) , then you use the toner, which brings the color to vr, then the clear coat. the cym uses a pearl instead of a toner. this makes blending the color a little difficult

daem0n

well hopefully black is a bit easier...lol I'll try to stay optimistic :P