Request for help: Rear sill

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little_joe

little_joe

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I really need to replace the rear sill on my 40. I have a replacement from Awl_Teq; and I'll be pulling stuff off the rear within the next few days (tire carrier etc).

I don't weld/don't have a welder. I'd like to ask for help with this, if someone is interested in welding in the new one. More than happy to come to you, provide food and drink, consumables, anything. The extra eyes in cutting out what's left of the current sill would be very appreciated as well.

Anyone interested in doing this some upcoming weekend?
 
@GLTHFJ60 I'd love the help and I can wait! Let me know when you have time an what all you want/need for this work.
 
I’m down for helping but just like Johnny I’m busy with work until after thanksgiving. Just post up when and where you will be working on it and hopefully I’m around that weekend to help.
 
I can help, I have a 220V welder, and I don't live far away.
 
I like to drink beer.
 
Has anyone done this before? I was snapping off bolts removing some stuff this morning, and I'm trying to figure out how much sheetmetal I can save (pass side outer skin is not bad, driver's side outer is gone) vs what kinda patching is customary.
 
Your more than welcome to come over to my place. I've got the tools you need; however, I doubt I'd be much help. When I replaced my sill I went home made. Bent up some 16 gauge plate and then made my own body mounts.
 
Here is what I am doing:

Remove everything that's in the way/needs to come off.
Picking at and cutting out the existing sill.
I believe the pass side rear quarter may not have to be cut out, just some small patches.
The driver's side will have to be cut out and a proper patch put in.
New rear body mounts.
I am going to braze in the new sill and cover, and driver's side patch. I can braze, just no welding. Idea is to take my time with this, cause as little collateral damage as possible, then get the sill "tacked" (brazed) and once done, stop by someone's place for finish welding.

The brazing will also increase the value of my 40 immeasurably since I have 99.9% pure silver filler. :)
 
Joe, I'm not sure about brazing sheet metal. I guess it is possible. I would think that it would require a lap joint and not a butt weld. If you are flanging and lapping the joints, why not just use 3M Fusor? That way it wouldn't even need to be finish welded. Glue it up, mud the joints, sand and paint. I have a feeling you are going to attempt to butt weld (tack) with solder. Maybe it's possible but I've not seen it done. Remember that flux contains acid. Are you sure you want that sitting on metal covered by bondo and paint?

Why not cut your patches, pre-fit them to perfection and use clecos or butt weld clamps to hold the patches in place? Then you can have somebody to weld them up. Clecos and clamps are removable, so you just take them off. Harbor Freight sells cheapo butt welding clamps. You will want to use the smallest ones available for butt welding.

 
X2 on the clamps! They make all the difference in the world. They also give you the proper gap to fill for a proper weld.

Here they are in use. Not only do they hold the gap they also hold parts flush and act as a heat sink as well.
336587_258017077562524_6369548_o.jpg
 
little_joe said:
Here is what I am doing:

Remove everything that's in the way/needs to come off.
Picking at and cutting out the existing sill.
I believe the pass side rear quarter may not have to be cut out, just some small patches.
The driver's side will have to be cut out and a proper patch put in.
New rear body mounts.
I am going to braze in the new sill and cover, and driver's side patch. I can braze, just no welding. Idea is to take my time with this, cause as little collateral damage as possible, then get the sill "tacked" (brazed) and once done, stop by someone's place for finish welding.

The brazing will also increase the value of my 40 immeasurably since I have 99.9% pure silver filler. :)
Click to expand...
You can braze any metal, as a matter of fact, it's easier to braze than to weld. For most (all nonstructural) applications, the two are equivalent.
@roadstr6 is correct about the joint though. A sheetmetal butt joint doesn't have the surface area to supply the necessary strength for an automotive joint that'll be vibrated to death. A lap joint, three times the thickness of the sheet, is the best you can get. I can give you the calculations, if you want.

I wonder about your motivation, though. Do you want to braze the joint because you don't have welding skills/access to equipment? If so, there are plenty of people who can help with that. Generally, I like brazed joints for hard to weld metals (anything not steel or aluminum) or parts that can't stand the weld heat. The sill can easily be spotwelded and the seam filled with body filler, or overlaid with fiberglass.
 
It just dawned on me (I'm slow on Tuesdays), if you're planning to braze the fill panels, you can gas weld them too. Either way is going to put more heat in to the seam than spot welding, which is something to think of if the repair is going to be made on the chassis. That thing's a big heat sink.

Also, as with anything else, preparation is key to success. You cannot braze or weld any metal which is not bare and clean. Well, you can, but it won't last. Also, your joint should be as clean and straight as possible; this minimizes the tendency for heat to flow out of the joint, making it weak.
 
Ok, I will revise the plan once I'm not at work and have time to really digest everything you guys have offered. This is great stuff, thank you all very much.

I thought about brazing as a kind of tack until I could get things finish welded. I've been brazing on 1:10 scale RC's and can minimize the impact due to the setup/tips I have - this includes heat and flux. I'm talking 2-3mm area. But it seems this is not a good approach, so I am glad I asked and even more grateful you all shared wisdom/advice.
 
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The rear sill is in the body, not the chassis.

Brazing would certainly be unique, but for a strucutural part of the body (rearmost two body mounts), I would recommend welding it in place, not brazing.

Joe, if you can braze, you can weld. Buy a welder already :flipoff2:
 
GLTHFJ60 said:
The rear sill is in the body, not the chassis.

Brazing would certainly be unique, but for a strucutural part of the body (rearmost two body mounts), I would recommend welding it in place, not brazing.

Joe, if you can braze, you can weld. Buy a welder already :flipoff2:
Click to expand...
Yeah, that's what I meant. It's Tuesday, bear with me.
 
GLTHFJ60 said:
Joe, if you can braze, you can weld. Buy a welder already :flipoff2:
Click to expand...

I've been thinking about it. I've done some welding, it's just my garage is already a cluttered s***hole. Although a welder would enable me to get rid of some clutter - namely, that roll cage I picked up a few weeks back.

Hmmmm.:hmm:
 
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