Need some opinions on two automobile projects

admin

Hey guys, I read here every now and then, but never posted much.  I have two questions that I can't answer myself though. The first deals with about 4 feet of frame of a Dodge Voyager. The bottom of the frame is rusted out (Read: Gone), and the sides are rusted maybe 5 inches up, it crumbles just touching it. I need to cut that off, and weld in a new frame piece.  My question is when I weld the new piece in, would it be better to leave a small gap, or just butt them together? I've never welded on an automobile before, and was starting to think of the shock absorption, or if the weld would shift around too much and crack. Also I will be using E6010 with maybe 4 inch welds every 4 inches, good idea? The second question deals with brackets on a Stake Bed that is used for dumping roofing debris. The brackets (angled, corner, L shaped, whatever) are bolted to the Stake bed, then bolted to a wood frame. The wood frame is bolted to a metal frame. Some of the brackets are rusted quite a bit, some are even torn.  The question is, in your opinion without seeing pictures, would it be a good idea to just weld plates over the brackets to reinforce them, or replace the brackets all together? The rust is mainly around the bolt holes, the edges of the brackets look fine (Weldable). I was thinking of buying new L shaped steel plates and welding them on top of the old brackets. Eeeeh, I hope this isn't asking too much. I just don't want to feel like I know what I'm doing, then later find out the welds cracked or the stake bed fell off the truck...on the highway...with a full load!
Reply:I forgot to add that it's around 33° F here. Is it stupid to ask if I need to preheat or keep an interpass temp or post heat temp up?
Reply:In my experience I've always seen the metal overlaped. I don't think a butt weld would do well. What are you welding back in? A frame part from a donor? Something you fabbed? That thing is unibody and may prove difficult to repair.Replacement is best in the long run.Last edited by dbc58; 01-22-2009 at 06:20 PM.
Reply:Originally Posted by zemzeroI forgot to add that it's around 33° F here. Is it stupid to ask if I need to preheat or keep an interpass temp or post heat temp up?
Reply:I do alot of frame work on cars, trucks amd rvs. If you could post some pictures of the frame you want to repair it sure would help. I assume this is not a unibody. When I do frame repairs I V weld plates on  either side. Example separate two fingers apart on one hand now insert a piece of steel between the fingers. Tighten you two fingers against the steel now try to push that steel with a finger from your other hand. Not easy is it, Idea here is that the steel welded between the fork V is much more resistant to  stresses. If you were to only use one plate of steel on just one side of the frame it susceptable to side stress from the opposite side. And if you were to only butt weld the pieces together : with that cap inbetween its susceptable to side stress from both sides! You weld might hold up but the piece or frame would twist from the stress.Co-Own CNC shop:Miller :1251 plasma cutter, MaxStar 700 TIG/Stick, & XMT 456 Multiprocess Welder.&  2 Hypertherm HPR260's Plasma CutterSorry I had a bad stroke but now I am back.
Reply:Alright, here is a crude picture of what needs to be done. I'll try to get real pictures soon. The first one deals with a Dodge Voyager. If the frame is square shaped, the bottom of it is pretty much just gone. The plan was to cut off the rusty old frame, buy a new frame piece from the junkyard and just weld it in place. I have never welded frames, and was concerned about what Specter said, stress and support. The second one, I'm not sure how to explain and is probably a question only I can answer unfortunately. There is a stake bed truck with rusty brackets holding the stake bed to the frame. Is it fine to just weld new steel over the brackets to reinforce, or should the brackets just be replaced. Each bracket is rusted differently. To Specter, for what you're suggesting, I would need three pieces of steel. One if the middle, then two to make the V shape? Sounds good, and much less work than what I was going to do it sounds like. Thanks for the replys
Reply:yep three pieces two reinforcing pieces and the new frame piece. The new frame piece will be sandwiched between the two side pieceses. Attach one piece to the existing frame and clamp it in place. Then bring the new frame piece  up to the existing frame with a gap to butt weld the old frame to the new frame. Then run  you butt weld and your run down the two pieces along your reinforcing side piece. Now position and clamp the other side piece and now run your welds along that second reinforcing side piece. Once cooled off steel brush then prime and paint to prevent rustGood LuckTomLast edited by specter; 01-24-2009 at 09:13 PM.Co-Own CNC shop:Miller :1251 plasma cutter, MaxStar 700 TIG/Stick, & XMT 456 Multiprocess Welder.&  2 Hypertherm HPR260's Plasma CutterSorry I had a bad stroke but now I am back.
Reply:I usually use a rubberized undercoating to top it all off since it will fill any unweldedjoints as seled them from moisture.Co-Own CNC shop:Miller :1251 plasma cutter, MaxStar 700 TIG/Stick, & XMT 456 Multiprocess Welder.&  2 Hypertherm HPR260's Plasma CutterSorry I had a bad stroke but now I am back.
Reply:Weld the torn brackets and then put new ones next to all of them and rebolt the stake bed to the frame just like the originals are. But it sounds like something is loose or worn at the point where the bed dumps/pivots at, or where the hydraulic cylinder is attached to the bed, causing the twisting of the bed. But it could just be uneven loading of the shingles causing the twisting of the bed during the lifting to dump it out. Hope this helps.Miller Thunderbolt 225Millermatic 130 XPLincoln HD 100 Forney C-5bt Arc welderPlasma Cutter Gianteach Cut40ACent Machinery Bandsaw Cent Machinery 16Speed Drill PressChicago Electric 130amp tig/90 ArcHobart 190 Mig spoolgun ready
Reply:Oh man, I'm starting to feel like an idiot. So here's another picture, heh.#2 sounds like the way to go. #3 was what I was going to do. The new donor (Junkyard) piece would just butt up against the old piece, there is no room for it to overlap the old frame. Thanks for the suggestion STwelder.
Reply:yep but the side plate in place then butt the new frame  up against the old frame. Run your butt weld  and then the other side plate.Co-Own CNC shop:Miller :1251 plasma cutter, MaxStar 700 TIG/Stick, & XMT 456 Multiprocess Welder.&  2 Hypertherm HPR260's Plasma CutterSorry I had a bad stroke but now I am back.