Outside bottom rear cab flange replacement
 

Does anyone have experience in replacing the outside bottom rear cab flange (just the bottom flange area, but all the way across the back of the cab)? Is this best created with a bead roller? Should it be with a male bead of perhaps 1/4 inch diameter plus a polymer wheel to "tip" it in the positive and the negative directions that are needed for the shape of the flange? Is there typically some shrinking and stretching to do after this is created in the contours that are needed? Any other suggestions on tools and how to achieve this? See image.

Re: Outside bottom rear cab flange replacement
 

... part of the reason I want to replace this is that the rear flange on the Counterpart cab corner is not very consistant/accurate compared to the original. Because of this, I might as well replace the entire width at the rear outer bottom flange of the cab. Thoughts?

Re: Outside bottom rear cab flange replacement
 

I don’t know how to help you, I honestly don’t see any rust through and only see some surface rust. Might be just the way my computer shows the picture too.

That is all a pinched and welded seam, maybe it’s been folded over some how as well.

I would say, if there is rust through, use some 16ga flat and recreate it, stitch welding to original.

Re: Outside bottom rear cab flange replacement
 

Thanks Clyde. There actually is some rust through in some areas in the curved areas. When wire wheeling, it broke through in some areas. Also, the Counterpart cab corner in that area is far from ideal - inconsistent flange and not a straight line but instead it is an arc. For these reasons, I was hoping to recreate the entire area. Perhaps I should purchase a low cost bead roller and try to bend these shapes. You are right that I have the option to just replace some areas instead of the whole thing. I may be able manage with just a bending brake and shaping with a hammer for the curves. I will post some better pictures later...

Re: Outside bottom rear cab flange replacement
 

Mine was ok at the trans tunnel and the flat lines off of them but i made my own "flanges" in sections by just hammering them over a 1/4 rod and welding a flat thin piece to that radius. it came out great and looked good. I just didnt replicate the spot welds. Having a roller would have been much easier.

Re: Outside bottom rear cab flange replacement
 

Thanks rideblue00 for the comment. It helped me to realize that I should be able to create this just using a small metal brake. (I did a small test piece...the bends look very close to the original) For the 30 degree radiused curves, I will simply angle each straight piece by 15 degrees (creating a sharp angle), then fill in with some pieces of curved metal to create the radiused curves. Like yours, this should look good when complete. Thanks again.

Re: Outside bottom rear cab flange replacement
 

I would make patches for the bad areas and just do those. That joint is the floor and the back of the cab and would be a huge undertaking to fab the replacement parts for the entire run across. As far as the cab corner goes I would metal work it to better fir the rest of the truck.
Jimmy

Re: Outside bottom rear cab flange replacement
 

Good point PGSigns. This decision, which plug welds to break apart and which to leave alone, comes up throughout these trucks, such as around the door openings etc. The perfectionist in me wants to do them all, while the practical part of me says many should be left alone and simply cleaned up. Your point is a good one because many of these trucks, being vintage, will not see constant use so just a good cleaning up of many of these joints is suitable.

Re: Outside bottom rear cab flange replacement
 

I made 2 separate orders and ended up with a Counterpart and a TriPlus cab corner, the Counterpart one went in the bin and the TriPlus fit like a glove. I ordered up another TriPlus for the other side. IIRC they aren’t too costly.

Re: Outside bottom rear cab flange replacement
 

For the angled curved sections next to the tunnel, I'd probably hammer form patch panels, on a buck form.

I would also vote for making patch panels, rather than replacing the entire lower section.

Re: Outside bottom rear cab flange replacement
 

66C10LB,
I had to replace the entire length of mine. It was in worse shape than yours. As stated that is the Cab floor and the back wall of the cab. I took a piece that was in okay shape and went to a local sheet metal shop. I had them bend me up a few pieces (8ft in all) with the right contour. I had to replace sections of the inner (floor) part as well. I cut the flange off. Then trimmed the back wall of the cab up another inch. That gave me the ability to weld on pieces for the floor so I was attaching good metal to good metal. I also cut it out in sections to prevent having problems with the wall sagging below where it should be. I cut out triangle pieces and re welded them to get the rounded parts. Sorry I don’t have any pic’s. I’m no pro but it turned out pretty good. I epoxy primed it after and seam sealed the inner part to try to keep dirt and moisture out. If you have more questions let me know. I’ll try to explain it better if needed. Good luck.

Vince

Re: Outside bottom rear cab flange replacement
 

Thanks Draco for the info re TriPlus. I think that I can get that through KMS Tools in Canada.

Re: Outside bottom rear cab flange replacement
 

Thanks Grounded63. Yes, I may end up not doing the entire length. Thanks for seconding that.

Re: Outside bottom rear cab flange replacement
 

Thanks Vince, For the detailed suggestions. I'll probably do something similar. I like that you replaced the inner (floor) metal as well. I'll let everyone know what I end up doing.

Re: Outside bottom rear cab flange replacement
 

There's a definite difference between the brands.
Triplus is thicker with better contours.
http://67-72chevytrucks.com/vboard/s...81#post8051881

Re: Outside bottom rear cab flange replacement
 

In case this helps anyone else, I finally found a solution for recreating the outside rear flange of the cab. I picked up a Bead Roller plus some optional die shapes and managed to come very close to the right shape by using a combination of several die pairs. Also, the bead roller can act somewhat like an English Wheel for straightening and smoothing after bending the metal into shape.

Re: Outside bottom rear cab flange replacement
 

That looks great! I had a local shop bend me up some patch pieces.
Yours look good with the angles . I had to pie cut a lot of pieces to make it all fit up was lots of work

Re: Outside bottom rear cab flange replacement
 

Jrusher, thanks. For the right side I did it much like you did . I will have to fill in the angle with weld material in order to emulate the bead roll bend on the left side. Either way, it is workable. Looking forward to seeing your progress.

Re: Outside bottom rear cab flange replacement
 

66c10lb you have done a fabulous job of recreating the center of the back lower cab wall.you need to start producing those panels for sale.that is alot better than the pie cuts most use when using the straight flange parts.alot cleaner looking.you are very talented.just my 2 cents.

Re: Outside bottom rear cab flange replacement
 

Thanks colins10672. Definitely took a lot of test pieces, trial and error until I got it looking close to original. Haha.. would loose money if I were to sell it. May get faster if I would do a few of them.

Re: Outside bottom rear cab flange replacement
 

Kind of late for the party here but if you just have light damage like in the photos you could talk to someone parting out the cabs and have you cut some repair panels . Drill out the spot welds and weld in . Perfect bends and it. I have sold complete side to side patches . Getting much harder to find a nice side to side patch but small patches are a little easier. If you figure your time , material, bead roller etc it might be something to consider . Thanks

Re: Outside bottom rear cab flange replacement
 

Good idea paulspickupparts. A bit hard to find in my neck of the woods. More of a vacation town / wine region.

Re: Outside bottom rear cab flange replacement
 

I was wondering if the bump in the middle could be eliminated during rework? Why not just make it straight across?

What purpose did the bump serve?

Re: Outside bottom rear cab flange replacement
 

I believe it has to so with drive shaft clearance. On that note, I know one person that simply welded the floor and the outer rear together without the flange shape. Personally, I prefer that things be as close to original as possible. It's a hobby for me so I enjoyed finding a way to replicate it.

Re: Outside bottom rear cab flange replacement
 

Have finished the rear flange of the cab by bead rolling the shape of the patch panels, welding new metal onto the inside rear floor, using cleco fasteners to hold copper backing behind the welds, then plug welding the flange (copper rich weld-through primer used in the plug welded flange).