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Fender flares


mender
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Got the new wheels and tires for the '95 Civic this week so today was fitting day. Previous wheels and tires were 205/50/15 Dunlop Z3s on 15x7 wheels, new combo is 225/45/15 Hankook R-S4s on 15x9s. Obviously a wider tire/wheel and needing more room under the fender. I figure other people might be thinking about this, hopefully this helps. :)

 

The fenders had previously been moderately modified to fit the 205s, basically just the inner lip folded and the fender pulled out a bit. For those who are going to do this, don't cut slits in the inner lip, just gradually massage it up into place with a hammer and dolly, stronger and no sharp edges (more later). The stock fenders have a flat section just above the tire:

image.png.577d2c2345433fdda3ee64f4799889f2.png

 

I started by pulling and hammering the edge outward to see how much tire there would be left to cover:

Civic1.thumb.jpg.42bdd8ab9f7c86e56dd6c1fd1cf7883b.jpg

Lots left to cover. You can see the ragged edge of the fender lip (courtesy of one of my teammates) and also the ridge left from the flat section.

 

After a bit of thinking, I figured the easiest way would be to move the whole fender out by cutting it at the crease beside the hood and adding a strip of metal:

Civic2.thumb.jpg.97d3a9a860b2d0b13906abd16d1cdec4.jpg

 

After positioning the fender to cover the tire, I slid a piece of paper under the edge of the hood and marked it:

Civic3.thumb.jpg.7a4a82ec2fb5a30249fb99b67e9b2c02.jpg

 

Then transferred that to the sheet metal, cut it out, smoothed the edge and welded it in:

Civic4.thumb.jpg.634c87398b82debd8c9ca70b1f4cba52.jpg

 

I lined up the edges carefully and tacked them, then stitch-welded to complete the weld. Fitting is very important for a decent final finish, the better the fit the better the result. I stitch continuously, starting at one end and going all the way to the other end. Each spot/tack weld is allowed to cool for about 1 second (red-orange) before the next one, overlapping and blending. Patience helps!

 

As does the right heat setting; I've seen some pretty ugly snot-gob welding by people trying not to warp the metal and using a very low setting. Barely melts the metal but ends up adding more heat because they have to hold the trigger so long! The trick is to have a high enough setting to produce a strong tack and use that to stitch the weld. On my Miller 175, (4 settings) I use one click more than I would if I were to do a continuous weld. Very brief tack means high enough temp to produce a strong tack but low heat so no warpage.

 

A bit of smoothing with a flapper wheel and some hammer and dolly work:

Civic5.thumb.jpg.6760262dfb7d58d9df93079c6ea53c83.jpg

 

Then I added a length of 1/4" steel rod to the outer lip, again fitting carefully before welding. Grinding then sanding with an orbital sander got the metal ready for some high build primer then see how it all looks:

Civic6.thumb.jpg.ea488cb44635e006802a0585ece256e7.jpg

Civic7.thumb.jpg.df9072863fdb6511ddf2020ff677cf1a.jpg

Civic8.thumb.jpg.7004497af62b956a9e43ecccb5ffb8b4.jpg

 

 

Covers nicely now, is quite strong and won't cut the tire if the edge gets folded in. Not show quality but good enough!

Edited by mender
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Backspacing is 6.3", I'll be using 15mm spacers (.6") to get to the 5.7" backspacing that I need. 

 

Your second question can be taken two ways so I'll answer both.

 

1. For initial positioning and tacking into place, I start at one end and tack the pieces in place as I go. That makes sure the middle doesn't end up buckling because one end wasn't aligned properly. I do the same thing when I rivet a panel together on anything but a dead flat join. Again, time spent making sure things fit ahead of time gives the best results.

 

2. One continuous weld/tack sequence from one end to the other. With this method, the tack weld is allowed to cool for a second and pulls the metal together, setting up the next tack. No need to jump around as the edges stay aligned nicely and the overall temp of the surrounding metal is low. If the pieces fit properly before the weld they'll fit properly after. Tacking in a continuous sequence when the last tack is red-orange melts the next tack into the last one and makes for a strong weld. I try to get myself settled to do the whole length at once so that I don't start and stop. 

 

The trick is to time the tacks so they overlap and blend to get a strong weld with minimal warpage. A couple of test pieces butt-welded together this way will help get the timing sorted out. Also, once you get everything set you can turn down the wire feed and get close to a fusion weld with very little build-up to grind off afterwards.

 

The usual weld one inch then skip to another section almost always causes warpage because of too much heat. As the metal heats up while welding the one inch part, it expands and can push apart the edges which causes a gap. The typical welder just fills that gap during his weld which messes up the fit and causes a bulge. 

 

 

I was very fortunate to have an old world metal shaper as my autobody teacher in high school who taught me much more than I realized at the time. He's from England and worked at the Jaguar factory, hand-forming fenders from sheet with an English wheel among other tools. He was the second fastest at 9 hours per fender; the other guy took 8.

Edited by mender
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Some more pictures: this is the inside of the butt-weld. The stock Honda metal is a little thin so not as easy to get a smooth continuous tack weld. You can see how low the temp was and the spacing of my tacks by the discolouration of the primer.

Civic9.thumb.jpg.396fadb1b8960aabf1a731cf2c75600d.jpg

 

This one shows a bit of grinding of that weld, plus the 90 degree weld to the fender flange. Again, continuous tack weld with good penetration but low heat:

Civic10.thumb.jpg.25adae1bdf0c2ec6efcc36aba42adcd1.jpg

 

And this is the 1/4" steel rod that I welded on the edge for strength and to get rid of the sharp edge. You can see where my "helper' cut the inner lip instead of just folding it back.

Civic11.thumb.jpg.31d05f5f3ca531fc31552c8b6de88bdb.jpg

 

Edited by mender
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Well done Sir.

 

We use a jig (home made) and clamps to keep the metal from warping on some of our fender flaring. Also the thicker gage of the metal is easier to weld. The thin metal you work with is not easy and takes an experienced touch. Outstanding work. 

 

And your heat recommendations are spot on. It is a lost art. 

 

 

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20 minutes ago, Black Magic said:

The eastwood rollers that bolt to the hub also work great. Strech about 1/8 ridge in metal and work it outward (roll back and forth as you turn knob to advance ridge outside).

How much can you get with that? Here's a stock one, has a reasonable amount of metal to work with:

image.png.5ec4245e74871e0b0ee9f61174da4118.png

I needed another 1 1/4" beyond flattening the ridge and I don't see a roller stretching the metal that far - but I could be wrong! :)

 

Edited by mender
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We pulled at least 2". It pulled the fender out at the hood (like your example) because that spot was softest initial rate. Hood still sealed so who cares. 

 

We cut new holes\opened up fender mount holes from chassis to fender. You will need to do this in spots, so you don't have to thin the metal as much (just reshape, not strech). For example at the bottom fender mount cut holes to pull bottom out 1", then your roller just needs to reshape (not stretch) the metal out up top.

IMG_65821.jpg

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Okay, didn't get much done today, watched the F1 race and then did some visiting.

 

Here's the rear. There was rust damage that I patched really quickly before our first race so the wheelwells were opened up a bit already.

civic12.jpg.3bbe42c5191bf0e51776c693e39b730a.jpg

 

Not enough metal to move around so time for some old school metal fab. A bit of this to start the shaping:

civic13.jpg.de3142a859c42268f34c76c3a6317b2d.jpg

 And a bit of this to smooth things out (I'm still getting up to speed on this):

civic14.jpg.5660a0dab76998f9e47613ca2303696b.jpg

 

And it's pretty close.

civic16.thumb.jpg.29d83c2136937df70f4e0658fa5f28a3.jpg

 

Will see if I can get both sides mostly done tomorrow, I need some more 1/4" steel rod for the last flare.

 

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On 9/3/2018 at 6:00 AM, morganf said:

How many points is something like that?

Material cost most likely (about 3 points) but given the latest trend for aerodynamic aids, I would guess 10 points max for a fixed point value.

 

I'm doing it to provide at least nominal protection from contact, can't afford to have someone's carbon fiber splitter/wing/canard slicing up my tires in the corners.  :)

 

Maybe I won't have to worry about other cars getting too close if I get a set of these hubcaps:

image.png.5c9050b66c587025e1c9fbb80308eb09.png

Edited by mender
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23 minutes ago, mender said:

Material cost most likely but given the latest trend for aerodynamic aids, I would guess 10 points max.

 

I'm doing it to provide at least nominal protection from contact, can't afford to have someone's carbon fiber splitter/wing/canard slicing up my tires in the corners.  :)

 

Maybe I won't have to worry about other cars getting too close if I get a set of these hubcaps:

Definitely material cost... I really like that you built some nice flares to contain the wheels. I'm a bit of a broken record about how much I dislike the wheels sticking out from the bodywork!

 

9.5.1 ...hub caps shall be removed.

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  • Technical Advisory Committee
2 hours ago, enginerd said:

Definitely material cost... I really like that you built some nice flares to contain the wheels. I'm a bit of a broken record about how much I dislike the wheels sticking out from the bodywork!

 

9.5.1 ...hub caps shall be removed.

  Yes when open wheels get together bad things happen . I think tires should be within the body and material points should be added to do so . Something else to consider when bolting on them big meats ..

   Another thing the TAC is working on I bett ..

 

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38 minutes ago, Ray Franck said:

  Yes when open wheels get together bad things happen . I think tires should be within the body and material points should be added to do so . Something else to consider when bolting on them big meats ..

   Another thing the TAC is working on I bett ..

 

I would not call this a areo thing, nor would I have counted points on OUR tech sheet if we were simply looking to keep the wheels from being exposed.

 

My $0.02

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Today's progress: both rear flares completed and welded on, still need the 1/4" steel rod inside the lip and of course some more white paint.

Civic18.jpg.5ab06aa0d660041d24f8f25fc0bb6922.jpg

 

So here's a before picture:

Civic19.thumb.jpg.13ad65a245f0f22387c0f804f5a5ebcb.jpg

 

And after:

Civic17.thumb.jpg.575406fe875f8065d5f9910ea247aacf.jpg

 

 

I think it looks a little sportier now. :)

Edited by mender
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