I have another frame question ! i am thinking i should go ahead and box my frame rails since i have my frame just about disassembled and was wondering if i had to weld the whole plating to the frame or can i put stitch welds on it about every 6" or so and is 3/16" plating ok to use.
Thanks Again Ernie

 

Fully weld.. stitch welding can leave weak points in the welds.. Boxing the frame the best thing you can ever do..

 

Not sure I agree on the boxing being the best thing for everyone; it depends what you're doing to the truck. The performance of the stock suspension and all the body mounts is based on the design of the stock frame, which is really quite flexible (hence rivets, not welds). If you are going to convert to IFS, then you need a stiffer frame to make it work properly, and boxing is a good deal.

 

Can i stick weld it or should i mig weld it, i have both but my mig is a pocket mig and it shuts off on temp alot.

 

Stick weld will do a good job.. Stick weld will also handle the thicker steel better than a mig would.. I would use a good mild rod ( god its been forever sence I stick welded)

 

If youre going to box it, weld it all the way and leave no openings. If you leave openings it's a route for moisture and dirt. Dirt contains iron particles. Moisture+dirt=rust

 

you could use 7018 without a problem i wouldnt use any wire smaller than .030.
.045 would be optimal

 

My opinion is to stick weld it since your mig sounds too light to get enough penetration. 1/8" (10 ga.) plate would be plenty thick enough for boxing, the strength is in the shape of the structure, not in the weight of the material. Do weld fully, but stitch weld no more than an inch at a time skipping back and forth from side to side, front to rear, top to bottom, putting your stitches about a foot apart, but doing each as far away from the last one as possible. After the first round, start again adding stitches in between the first set. Each weld should fully cool before doing another near by, continuing the pattern until it is fully welded. A trick to getting a good looking and structurally sound boxing is to cut the plate so it fits snugly inside the rails, and inset it about 1/16" from the edge (you may want to tack it with the mig) this will give a nice inside corner to weld in and be much easier and neater to clean up. If you can't lay down a clean enough bead to look good without grinding, you may want to take the tacked in frame to a good welder to finish with a tig machine. If it were mine I'd spray the inside with weld thru primer before welding.
DANGER!: Make sure you pre plan how you are going to install/ remove all parts attached to the frame before you start. Unless you drill access holes you will not be able to reach any nuts or bolts inside the frame once it is boxed, and anything you want to attach after will require a tube welded in for the bolt to pass thru and tighten against or a threaded blind nut put in. Don't expect to be able to just drill a hole all the way thru and put a bolt in, you'll just crush in the sides. Be sure to set the frame on stands or better tack weld on legs so it is level side to side and front to rear and take and record diagonal measurements from known reference points before starting to weld. recheck and correct any warpage or twist after each round of tacks. It's too late to fix it after you finished welding the plates in solid, if you have warpage or twist at that point your frame is junk.
PS: Unless you are planning a lot of HP (> 400 HP) in the drive train, the risks and problems created by boxing far outweigh any benefits of strength or appearance, and even if you are there are less risky ways of strengthening the frame. Remember this is a working TRUCK frame that has survived 50 years of use already, not a lightweight model A car frame that requires boxing to survive installing a V-8.

 

Good thread....I was going out this morning to buy material to box my frame. The reason is because I removed the #2 xmember. I can put pressure on the front running board bracket now and see it twist. It didn't do that before, otherwise I probably wouldn't bother.

Ax....here comes another dumb ?. What is weld thru primer? I thought about painting the backside first, but I knew the paint would just burn off at the weld. I'm going to use a mig, so would paint/primer contaminate the weld area, even tho it's on the backside?
_____________________
XFM

 

Weld thru primer is exactly that, it is designed to be used on metal where rustproofing won't be possible after welding. It is primarily zinc metal particles with a carrier that won't comtaminate MIG or TIG weld. The zinc will actually form a galvanized corrosion resistant coating when heated. It can be brushed or sprayed on and does come in spraycan as well, but that's an expensive way to apply it except in small areas. Check with your pro bodyshop/paint supplier or welding supply shop for it. Ford also sells a similar product to their dealer's bodyshops for use in warantee repairs.

Xfordman, I would recommend putting in a "X" type crossmember to stiffen your frame, unless you will be in the high HP/high torque range.

 

AXracer, i was shooting for about 400 hp that's one reason i wanted to box the frame but after reading your thread i'm not so sure i want to attempt it or have someone else screw up my frame by not welding it properly. Would you have any other feasible sugestions to strengthen the frame to handle this kind of hp.

 

Yes, to improve rigidity and strength take a lesson from the automakers and add a modified X or K member. Picture your chassis from above with the driveline in place. I'd make two mirror image pieces out of 2x3 rectangular tubing on edge using 3 pieces for each side. describing one side: Start with a bolted in mounting plate inside the frame at or slightly forward of the firewall. Angle the first piece of tubing back to a point on the tranny tailshaft where it narrows. Another plate bolts inside the frame at the front hanger for the rear spring, and a piece of tubing angles forward to about the middle of the driveshaft. connect the two pieces of tubing with a third piece parallel to and just alongside the driveshaft. Repeat on the other side of the truck. Now you must decide if you want to ever remove this bracing or not. If yes (I always want to make as major a piece as this removable) make two connectors to bolt in between out of 1x2" tubing laying flat and 1.5 x 1.5 angle iron that loops over the driveshaft as close to the floor as possible. These could also be made from 1/4" plate 2" wide. one connector should go over the driveshaft just behind the front universal joint, and the other near the rearmost end of the two parallel pieces and arch up almost against the floor. A third connector can be made to loop under the driveshaft beneath the front connector to form a driveshaft safety loop if you are planning to drag race it or do hard stoplight launches. Even if the top connectors are welded in, bolt in this lower loop to make it easier to remove the driveshaft and/or tranny. (speaking of which, the tranny mount could be attached to this assembly or if it is a crossmember made to pass thru and become part of this bracing) This should make for a VERY stiff chassis. If this still isn't stiff enough for you make a diagonal tubing brace from the front top of the frame just behind the radiator panel to the upper firewall just inside of where the hood hinges attach. Add a doubler plate on the inside of the firewall, making a firewall sandwich.
The only way I know to make it any stiffer is by adding a full rollcage. and/or tubular frame.
If my description isn't clear, email me and I'll draw you a detailed drawing.