Some advice needed on boxing a frame

I recently purchased a set of 1/8" boxing plates for my completely stock Model A frame. The frame has been sandblasted and checked for straightness and everything looks good.

I do have a few questions to ask before I begin though.

1. Like most folks I don't have any kind of frame jig to use. I know that some people without frame jigs just place the frame on level ground and then add sandbags or other weight to the rails to help keep them from warping. Is this necessary or would I be OK leaving the frame supported on jack stands and just working EXCEPTIONALLY slowly welding (MIG) just one or two inches at a time and alternating locations frequently? I'm OK with the welding process taking a week or more to complete.

2. The boxing plates I bought are a 6 piece set (3 pieces per frame rail). There is one piece that goes ahead of the stock front crossmember on the frame 'horn' area which I haven't decided if I'm going to use yet. There is also one piece that runs from the back of the front crossmember to the center crossmember area and the last piece runs from the center crossmember area to the rear crossmember. I'm planning on keeping the stock front and rear crossmembers in place but won't be using the center one as I'll be installing a V8 and different transmission which will require some sort of different crossmember later. I want to remove the center crossmember to box the frame but I don't want to have the frame get tweaked when I take it out. I found some 3/16" thick 1.75" angle iron and was planning to weld this across the top of the frame near where the center crossmember is located. Do you think this would be enough to keep the frame intact without the original center crossmember? I have enough angle iron to run another piece across the frame in another location as well- possibly somewhere across the bottom of the rails or further back on top of the frame rails- would this be even necessary? Would a second temporary brace across the top be better than adding one across the bottom?

3. Would it be a good idea to weld in another 1/8" thick plate behind the boxing plate where the engine mounts will be located? I planned on bolting the mounts to the frame and thought a little extra 'meat' to help support them might be a good thing. Overkill?

4. Notching the boxing plates slightly to fit tightly around the front and rear crossmembers shouldn't be a problem should it? I want to leave them in their current (stock) locations.

Thanks for reading through all of this. I've never done this before and don't want to screw it up.

Jay

 

hey Jay, welding the edge of the flange won't make your frame pull up or down, it will however shrink the inside edge of your rails and put a nice bow in them. you can try X bracing the frame, but I doubt it will be effective. your best bet is to either try to straighten them after they cool with a porta power or jack and chain, or shrink the outer radius's with a torch and a spay bottle. I would reccomend the porta power or jack. as far as your other questions it's hard to tell without pics

 

I just kinda passed this step. I used the front half of a stock frame, cut right in front of the cross member, and used 2x3 box for the rest. I tacked it on a table set the whole thing on jack stands leveled and squared it and tacked my plates in. Then stitched welded them. Frame is still square and level.

 

I boxed my whole frame without a jig or table. I welded no more than 2" at a time, kept checking for diagonal and flat. I ended up with 1/16" out in the diagonals and 1/8" out in the flat, which I thought was perfectly acceptable. I had it bang on, but then had to move the steering box mounting, and sure enough it moved.

 

Thanks for all of the input, guys. I appreciate your insights.

I think I'm going to try to do the welding with the frame up on jack stands. My plan is to weld a brace just behind the center crossmember on top of the rails and another brace just ahead of it on the bottom of the frame rails. I'll do this before I remove the center crossmember and hopefully it will help hold everything in place.

After that I might even set the rear differential I've been kicking around the garage across the back of the frame rails just for a little insurance.

Then I'll just go exceptionally slowly and really take my time with it. If there should be any warping I'll try the port-o-power to straighten things out afterwards.

I'll keep you guys posted with how it goes.

Also, here is a good thread I saw on the subject that may be of interest to some.

http://www.rodandcustommagazine.com/techarticles/0708rc_boxing_the_frame/index.html

 

http://www.jalopyjournal.com/forum/showthread.php?t=298378 Check this out before you start. An excellent low buck method to box your frame.

 

What I've done, build some 8 foot long sawhorses, good sturdy jobs, mount the frame level with shims as necessary, clamp it down with large C clamps. I've not had a problem ever with movement, built more than a few frames from scratch that way. Take your time, go slow and it'll go well.

 

Jackstands and shims and a very good level. It will try to curl, so the shorter the tack the easier to slice with the cutoff wheel when correcting. I put a plate inside the "Z" and where I added the dogleg drop in the back.
First I put the car together mounting lever shocks, steer box, all the stuff to bolt on, Xmember, so the nuts or threaded bungs can be tacked in place. Put in tubing for thrubolts, (crush tube) weld the nuts good.
Mine ended up 1/8" off, who gives a turd, it ain't a piano it's a old car.

 

Put all your new cross members in first. (Trans rear ) i cant figure out why every one puts there cross members to only the boxing plates 1/8" verus frame that is 3/16 and as everyone said welded in in spurts then ground.

Yes it is more work but makes for a much stronger frame

 

This is what I planned to do. It will make boxing more work. But if the crossmembers and bracing are in, it seems the frame would be stronger and less likely to move.

I'd let you clamp your frame to mine, but I cut mine up.