Pinch weld jack point paint damage?
 

So I jacked my car up this weekend to do the usual tire-swapping work, starting at the front and then moving to the back. I picked up some jack stand pads, thinking they would protect the finish.

Turns out no.

The pinch weld cut down in to the pad, and the pad material A) kind of scraped away at some of the paint, causing some to flake off and B) caused the layers of metal to separate slightly at one corner, kind of peeling apart. When I took the jack stands out the stupid pads were stuck to the car :@

Anyway, how should I go about touching up an area like this? I figured I would clean it with dawn dish soap, wipe down with alcohol, and then apply... something.

Any ideas?

I believe they make a rubberized under body paint in a rattle can. Or you can just go with the regular primer/paint setup.

Yeah, sort of what I figured.

Should I try to flatten it all back out?

Did you bend the pinch weld? I was under the impressions you just scrapped the paint off.

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I bent one layer I think? It sort of turned up a layer of metal like a book page (slightly though, it didn't even bend all the way to the weld).

I will take a pic this afternoon to illustrate what I'm talking about. Describing it is difficult :(

That happened to me before on a past car. The previous owner must have jacked the car up from that side to do his oil changes. If it bothers you, you can use vice clamps to straighten the pinch weld back out, then coat it with underbody spray. May want to think about using a pinch weld adapter of some sort.

I fixed mine because the factory jack wouldn't work with the bent pinch weld.

I use hockey pucks. They are harder and will not cut. So far on my BRZ no damage to the pinch weld or the paint.

Get one of these:

http://www.purems.com/images/product...34235_1_dp.jpg

http://www.purems.com/Products/PROTE...-Lift-Jack-Pad

Those look great but are so spendy. It's just a chunk of poly, after all.

I'm not sure how you guys are installing hockey pucks on a jack stands. Anyone have a link to a DIY? I've only seen how to do it for jacks

Lift it from the front subframe and rear diff instead...pinch weld damage is always bound to occur.

Of course :) got a floor jack just for this but I hate the idea of working supported only by the jack. So I put the stands on and this jazz happens.

For swapping wheels/tires, I never use jack stands, because I'm never under the car. Just a floor jack with a hockey puck (with a slit cut in it) to protect the pinch weld, and I lift one side of the car at a time. Works great, no damage to the pinch weld or paint.

When I do need to use jack stands, I have some poly jack stand pad protectors that I believe are made by Prothane, that I bought at Summit. They do not get cut by the pinch weld when supporting the weight of the car, even on much heavier cars like my Mustang.

I may end up using this method and just using the front and back jack points to quickly swap the tires. Seems like the best alternative, and honestly I spend more time farting around with jack stands than I do changing the tires!

I had the same problem with these jack stand pads as well. The pinch holes on the pads were so small that the car's pinch welds didn't slide right in the middle of the pad, causing the paint to rub against the pad and flaking.

I put some touch-up paint on the pinch welds to cover up the bare metal. From that point forward, I only use the jack stands. They have a pretty flat surface and only the bottom of the pinch welds touch the jack stands.

This is exactly what I do and it even works with my wife's Q5.

-Dennis

Okay, the slot is cut deep enough so that the pinch weld doesn't touch the puck?

And where do you place the jack? in the middle of the sill on that side, or on one of the points? to lift the whole side of the car I would think it would have to be toward the middle, but... enlighten me! I don't want to accidentally twist my car, lol.

The best way to lift the whole front of your car is either by the subframe or two jacks on either side pinch weld. Jacking them up equally little by little. Lifting up one side all the way by the pinch weld will twist the car and may cause the weld to bend. My jetta is a unibody (idk if the frs is), and when I have one side jacked up too much I cant even open my passengers side door because the body is flexed so much.

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hmm what about adaptor?

No, the slot on the hockey puck isn't deep enough to keep the pinch weld from touching the puck. If it would be, the puck would be cut in half, or very nearly so. I cut the slot in the puck about halfway through, to preserve the integrity of the puck, much deeper and I would risk the weight of the car cutting the puck in half. I've used the same slot-cut puck on all six of our cars (several much heavier than the BRZ) to jack it up on the pinch welds and never had any damage to the pinchwelds whatsoever. If you are really concerned about not jacking against the pinch weld directly, you can use the Flyin' Miata jack adapter, I have one and it is a good piece, but still use the hockey puck most of the time.

I always jack at the stock jack points on the pinch welds on all of my cars. The pinch welds are reinforced at the stock jack points, and on most of my cars that are low to the ground with limited suspension travel (like the BRZ, Mini, Miata) jacking at the front point will work to lift both tires off the ground on that side.

There is no risk to twisting our cars by jacking up at just one jack point on the side to lift the entire side of our cars.

Yeah that's why I said with my car because it's a unibody and that I wasn't sure about the FR-S. Thank god for that, I'm so tired of the creaking I get from my car being unibody lol slammed + unibody = a lot of body flex and creaking.

Yeah, I've had my share of VW's in the past, including the Jetta my wife owned we when got married, and they were all quite a bit more flexible than the BRZ is.

Of course the twins are monocot or unitized body construction.

Not sure they even make cars body on frame any more.

Just about every pickup / truck is body-on-frame, but I think we've seen the end of the BOF car days.

I won't miss them :D

Raising this thread back up since I got my car last month. When I cut the hockey puck, would it be okay for the top hockey puck to come into contact and support the weight of of the topside of the pinch weld where it becomes part of the foot well area?

Or am I suppose to have slot of hockey puck only touch from the bottom of the slot of the hockey puck to the bottom side of the pinch weld? I hope what I am describing makes sense.

the bottom of the pinch weld is not supposed to touch the puck. look at the yellow jack pad supporting the pinch weld in the other picture to see.

Using a small block of softwood with a slot cut in it works fine and is easier to make the a slotted hockey puck as well as thicker.

Some aluminum construction looks a lot like body on frame: Corvette for example.


A lot of smaller trucks are now unibody including the latest Jeep Cherokee which is a fat Dodge Dart, built like the Ford Escape which is a fat Focus.

Unibody gives excellent torsional rigidity. Jacking torsional stress is nothing compared to high speed cornering.

I recently damaged my pinch weld too....bent the whole pinch weld point, and it even split open slightly. I managed to pry them close but the paint damage was pretty bad. So I bought a can of "Valvoline Tectyl 506" to spray over the pinch weld.

This, and other similar products, are regularly used and recommended by 4x4 guys to prevent/protect from rust. The only downside is that it dries to an amber like colour...but luckily my car is orange (hot lava) and the pinch weld area is out of sight.

Okay, so the topside of the yellow puck touches the rocker panel? The channel is deep enough where the bottom of the pinch weld never touch the puck? Just want to confirm my understanding. Thank you

Yes. Again, look at the photo.

I notice the most damaged is done when you lower the pinch weld on a jack stand, that's where mine is personally bending, not when you jack up the car.

Yes and NEVER use anything between a proper jack stand and the car. A jack lifting plate can be applied under a block or pad of some sort but that's only because you NEVER work under a car supported only on or even partially by a jack. Period.

Spacers must not be used on jack stands.

I just bent a pinch weld tonight. Depressing as hell. I'm trying to be careful, lowering the jack slowly (lifting by front crossmember) and putting jack stands placed ever so carefully in the right spot. Problem is my jack doesn't lower perfectly smooth, even though its brand new. Car dropped quickly about 1/4in or more, meeting the jack stands and bent the passenger side pinch weld.


Should I be doing this differently? Seems a ridiculous way to support a car. My Corvette you just slap in pucks and you're set. These pinch welds are just silly and looking to get bent and paint removed. The other jack stands I have are grooved in a Y and too tall as they clear the pinch weld completely and support the car by the underbody.


Thoughts?

I bent my jacking point a little. Any recommendations on how to fix it

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It kind of is what it is. I'm not going to obsess over it because unlike the corvette is is a pinch weld covered with rubberized paint rather than a smooth rocker.


I have one set of stands where the Y isn't so deep and the pinch weld will drop all the way in. I have another that have a deeper Y and like yourself I was concerned about supporting the car from the bod as you were. I studied it for a while and decided that the small span of the saddle supporting the body adjacent to the pinch weld just simple could be that big of deal from a structural standpoint. If it were me I would straighten the pinch weld back to vertical using vice grips and paint the metal with plastidip or undercoating to protect the metal and not give it another thought. Initially I had taken a puck an cut a groove in it for the pinch weld to drop in. What I didn't like about the was now I was relying of the Y saddle of the jack to not slip off the puck. Decided against that before even getting under the car as it wasn't stable and not worth the risk. I now lift the car from the center front lift point. Place two jack stands under the pinch welds and lower it slowly. Then lift the rear by the differential and place two under the rear pinch weld and lower it into place. I use the stands with the deeper saddle at the rear point of the car. and lower the care slowly. Again the rear is being supported not by the apex of the pinch weld I also turn the jack slighty as to keep the supports as close the the pinch as possible. I use some pieces of leather from an old belt so that it's cushioned to some degree rather than metal on metal.


I understand where your coming from but if you look at nearly all modern economy cars this is how they are built. A good friend of mine has been a body man for thirty some odd years and he said I worry too much and to stick the stands under there and get on with the project.


regarding the lowering technique, you have to get good control over the handle and release it slow. I little lubricant on the jack can help smooth that out.


Anyway, don't stress over it too much. Straighten it out. slap some rubberized paint on it and move forward.

This is exactly how a bodyshop repaired a bent pinch-weld on my old STI hatch. Straightened it with vice grips and sprayed undercoating on it.

I'll just add that the pinch weld will be weaker after repair, so be careful with that one if worried about it.