Weld or Glue Fenders

johncmng · 05-22-2007, 10:13 AM

I'm thinking about flaring out my Carrera. What is the best method to go about this? Should I get the rear steel flares and weld them on or get the whole rear quarter panel (fiberglass) and glue them on? They're going to cost about the same. Which one will hold up better in the long run? I'm not going to do the work myself. Which is easier for the body shop to do? Which way is it likely for the bodyshop to mess up? Any one in the San Jose area willing to come over and do this for me?

Thanks
John

BeauBlues · BeauBlues's Garage

Welding steel flares will definably hold up longer than gluing on fiberglass. Plus the fiberglass will eventually show a line in the paint where it meets the metal. By my understanding, you should only get fiberglass fenders if you need to save the weight.

Ron.G · 05-22-2007, 10:54 AM

Steel flares. I have used the 3m glue on other things (not flares) and it is super strong. Most repair shops use it on newer vehicals for door skins, roof panels, rear quarter sections ect.
It think you would tear the sheet metal before you could seperate the panels.

You wouldn't have to worry about distorting the metal with heat from welding...... I would have no problem with adhering flares on as long as you follow the manufactures directions.

Wil Ferch · 05-22-2007, 11:45 AM

None other than Kevin Jeannette of Gunnar Racing...the very famous Porsche racing restoration shop in Florida...shows glue-method for fender flairs. Look at the "build-up" of various cars on their very interesting and entertaining web pages.

http://gunnarracing.com/index.html

- Wil

johncmng · 05-22-2007, 12:04 PM

Thanks for all the inputs. Looks like gluing may be the way to go.

IROC · IROC's Garage

My steel flares were bonded on over 10 years ago and look great to this day. No problems at all.

911-1978 · 05-22-2007, 01:32 PM

If you can weld them, do that, once you weld them they won't move there will not be issues if you do the plastic work and let the car sit and shrink before you paint it. I have two 911s in my shop that the flares were glued on and both are having major issues. The company that supplied the structural adhesive (which will be nameless at this time, due to pending litigation) doesn’t return my phone calls, came to my shop and can’t figure out why it is happening. Their answer is grinding the cars down and starting over, but they can’t guarantee it won’t happen again. To top it all off their sales reps comment is that they won’t cover labor, but they will supply me with sand paper, how big of them. Just curious how many guys have work done on there 911 and the labor charge is zero.

Although I will admit that using the structural Adhesive is very complicated, put the tube in the gun, squirt an inch out to make sure it is mixed and apply. Tomorrow, I'm going to take a big step and try to learn how to tie my shoes.

ed martin · 05-22-2007, 04:59 PM

I've tried it both ways. 3M epoxy and MIG welding. If you use the epoxy, preparation of the mating surfaces and clamping are critical. It seems that when you clamp, you need to allow some thickness of adhesive for the work to bond effectively. Any shortcoming in the process and you have to start over. Since learning to MIG weld, I've found that process and the results to be far superior and actually easier for me. The only reason to use epoxy is if you don't know how to weld as far as I can tell.

rattlsnak · rattlsnak's Garage

done both a few times, other than cost, no real difference if you use good glue, (3M). I glued some onto my SC @ 10 years ago, and you can still pick the car up from the outside of the flare lip with no seam signs. With todays glues, glueing is fine. Steel costs more. Maybe not in labor, but in parts..

Dennis Kalma · Dennis Kalma's Garage

I am getting rid of the sunroof on my '89 project, have oscillated between glueing and welding, the considerations being those in this thread.

My main worry with glue is that the seam will begin to show through the paint on a panel that is visible and curved as the roof (or fender).

Am I right to assume that the glue may in fact show a seam through the paint or am I just a worry wart.....any experience with finish on higher visibility panels?

Dennis

rennch · rennch's Garage

I had the same dilemma, and asked it in this thread:

http://forums.pelicanparts.com/porsche-911-technical-forum/321621-long-term-results-glued-flares-2.html#post3131863

honestly, I think they each have pros and cons. I might weld my rears and glue my fronts just to see how it goes between the two.

ed martin · 05-23-2007, 09:52 AM

Maybe for an area such as a sunroof, I would consider gluing. I don't think you have much to worry about in terms of stretching or flexing. Also small corner areas that are too hard to access for welding would be another gluing scenario. All said, I think I would be more inclined to weld just because the result is immediate and stronger.

By the way, back in my glueing days I modified one of those Simpson epoxy double barreled glueing guns to do the job. You pick one up at Home Depot for $20-$30. The ones you use for epoxying foundation bolts for siesmic retrofitting. Oh well, maybe if you live outside of California they may be hard to find.