I got a Model a frame Im currently welding weld nuts onto for the fenders for my model a tub. I actually have two frames, both square to within a 1/16" or less measured from the old pete and jakes article. I want to box the frame but dont have a jig. I have a garage floor but im building the frame on the side of my house on jack stands. Its on somewhat level concrete but Im going to make sure that its level with a carpenters level before I start to weld. I plan to have the frame with boxing plates tacked and two extra angle iron pieces tacked between the front and center crossmember and between the rear and center crossmember. My first question is with open drive, 40 rear (spring perches for over axle) and a 283 sbc and a t5, should I removed the center crossmember before or after starting to box it? I have some angle iron I plan to tack in to maintain the squareness of the frame? Is this a good way to go about it? Second question is if I just have the frame sitting level on jack stands, and go to weld the frame, will I experience a lot of frame warping if I take a very very long time to weld in the boxing plates in 2" increments? What is the best method of making your 2" or so beads on the frame? For a roughly 100" model a frame rail, start on the four corners of the frame and do a 2" bead top and bottom in those 8 spots? In an X pattern? Left front, right rear, right front, left rear? Let it cool for a while, maybe even room temp. Then go to the center at 50" and do 4 beads top and bottom there, then let it cool. Then go to 25" from the front and rear and do the same thing laying 8 beads total? Keep repeating this process, letting it cool for like an hour between each 4-8 beads I do? Or is it better to do 2 or 4 beads of 2" length changing from top to bottom? Does the frame need to be fully welded? It looks nice but is it actually mandatory? Im running full fenders and dont plan on having much of the frame showing. Does getting the frame level just mean-- I ***ume it is just making sure its level with a carpenters level on the frame rails? Would placing weight on the frame help get rid of warping even more so? And how would you set say engine blocks onto the frame rails and not have them slide off to provide that weight (if that would help)? In any case, I hope my questions make sense. Again, a frame table is something thats out of the cards for me. I'm only building this one frame so I dont see the reason to have a whole jig.
To minimize welding distortion, I suggest skipping around with your welds. Say 2” of weld every 24” and let it cool to ambient. It will take forever to weld, but it will keep it as straight as it will stay. Another idea is to build some stands that u can anchor into some concrete right next to the frame at the corners. Once the frame is leveled and square, weld the stands to the frame. After u are through with boxing the frame, you can cut it loose from the stands.
Hot rod frames have been boxed forever in less than ideal conditions...Tex Smith did an article in Hot rod magazine boxing the 32 rails in Sam Conrads roadster, He was flopping it around in the driveway while his dad Carlos was blasting it with an arc welder Do the best you can to make sure its square and flat and hopefully tie it down. Tack weld angle across the frame in several places and remove the center crossmember. Tack in your boxing plates and move around with your welds as not to build up excessive heat. I would also figure out what trans crossmember you are going to use and tack that in before removing your angle stringers. You can pm me if you wish since your Local.
Check around your area and see if you could borrow a pair of heavy metal sawhorses. No only will it get the frame at a more comfortable height for welding you will be able to clamp the frame down so it's more stable. I always had a couple pair of heavy saw horses around the shop when I was in the ch***is business. Always had a frame on them for various reasons. I still have the heavy ones in storage and a lighter pair here at the shop. Many years ago I remember seeing a very famous ch***is builder doing a deuce ch***is on a pair of saw horses. Worked for him.
Another option is to used already welding frame rails. https://www.speedwaymotors.com/Spee...Sf0zcp0ay1MHSnbrhGA4ftcN49fXNmpYaAoM2EALw_wcB
Do the best you can but don't overthink the project. My model A rod was finished when I received it, with no boxing. Without dis***embling the car, when we replaced the differential and put in coil overs and triangulated four bar, we boxed as needed to make it work. Later when we did an engine transplant, we boxed from firewall to front cross member. All this was done on a fully ***embled rod on the garage lift and also working on the floor while set on four wheels. Was it perfect? I doubt it. But I put another 110,000 miles on it after the above work, with no problems and lots of smiles.
All good info, I do not think having it 100% full length welded is necessary. @porkn****** and I were actually just talking about that this week.
I leveled my frame on saw horses. Checked it for square by measuring from right rear to left front and right front to left rear. Just pick a couple holes front and back for reference so you know where you are to start out. If it is not square get it square first! I got mine to within about a 1/16" of square which is better than it came out of the factory. Then start fitting your boxing plates tacking as you go and rechecking your reference measurements to make sure nothing has moved. Once tacked in and if everything is good start welding but keep it to short runs and skip around a lot. Don't build up too much heat in one area.
Yep, me too. Put frame on saw horses, lay 3 yard sticks across it standing on edge, one on front, 1 in the middle and 1 one the back. Then just shim between saw horse and frame until you have all 3 yard sticks flat and go to tacking. Check out my thread on building your own model A frame and there's pics on how to level the frame, takes about 20 minutes and works great.... .
I like the idea of heavy saw horses. If I find some that are heavy yet don’t take too much space, I’ll probably spring on em… space is a little tight. As it is I have a 1.5 car garage which fits a model a, model t and a work bench fine but not much else haha I will probably go ahead and PM you. I have a little angle iron I got from industrial metal supply to weld to the rails. As well as a rear hairpin mount I plan. Is removing the center crossmember mandatory I’m ***uming before welding boxing plates but after tacking? I’m ***uming it only works if you are doing a traditional av8 style build or closed drive, with an early ford trans. I was wondering this too. I guess the biggest question is if I have the motor mounts welded to the inside boxing plate, would I want it fully welded at least there? It does look better fully welded but I’m a novice at this and think I might be better off just skipping around. also as far as removing paint goes for welding, should I removed just the paint on the edges and maybe a 1/2” into the horizontal part of the rail and boxing plates for both the top and bottom and inside and outside?—-if that makes sense Other pic is for the k member I was thinking of fabbing. What is a good size stock for a k member? I have a piece of 2x2’ square tubing that’s 3/16” thick. Is that good enough? thanks for all the responses guys, I really appreciate it! Gordy
Putting weight on the frame isn't going to stop any warping that happens. The warping is due to microstructural and resulting dimensional changes from the heat. If you have weight on the frame, you would still need to apply heat in the warped area to return it to its original dimensions. I don't recommend this. Having the frame level and square and secured somehow before welding will ensure the dimensions as much as possible. Keeping the warping out is your job with being careful with how much heat you're putting in to each area. You could have an elephant on it, but if you weld each rail end to end continuously it will spring to whatever pretzel shape when you remove the elephant. You want to have it secure so you don't allow it to move while it's cooling, but more weight isn't going to make a difference. Regarding paint removal, you need to remove all paint from the area that will be melted during welding, plus give yourself a bit of extra room because that paint next to the weld will get burnt off anyways. I would take off all paint on the edge and at least 1/2" past the edge. Your frame was already stepped in the back to lower the back end. Do you know how it was done? Fully welding is not only about strength, it's also about having fewer stress concentrations. Fatigue cracking is your enemy, and stress concentrations are part of their fuel. Any area where you haven't welded the boxing plate can be an area for cracks to start in the welds. Fully weld it for peace of mind and to have less potential areas for cracking to start.
You could box the front and put in an X member from a later car, or buy aftermarket. I went a little overkill with mine and did the boxing plates with holes and a x member from Dagels (I couldn't find a stock x member that I didn't feel bad about cutting up).
Check that it's straight before boxing, they sag right about where the cowl mounts due to the rear motor mounts. A string should touch from the rear just ahead of the rear crossmember to the front crossmember. Not hard to correct with a 4x4 timber and a bottle jack, sit it on a couple of jack stands on the timber (front and back) chain it to the timber and push it up at the low point with the bottle jack.
I didn't say partial boxing, they were asking if it should be fully welded. What my comment was referring to was if, say, you only welded it in 2" increments with 2" gaps all along the length. This would have much more likelihood of crack initiation at the start/stop of the weld bead as compared to welding the full length of the boxing plate.
You mentioned partial boxing, and I replied with what to do to the boxing plates if you ever do partial boxing to lessen the stress point.
Read it again. I didn't mention partial boxing. I was talking about the discussion in this thread regarding whether the boxing plates need to be fully welded. Different conversation than what you're thinking of.
Pretty sure @raven ’s ch***is does not have the entire length of the boxing plate welded in and has been on the road for 15+ years running motors between 450 and 600+ hp the entire time ripping off crazy low quarter mile times and tons of real world street driving and it hasn’t got as much as a smudge of a crack beginning. I’ve seen it discussed boxing a half a rail would result in a stress spot where the boxing ends but I’ve never heard anyone say not having the entire length of the boxing plate welded in would cause issue
The truth is that only an LPI inspection of the frame can prove that claim. I investigate failures including weld failures. Your comment regarding partially boxing a frame rail is correct. I've investigated failures in holiday trailers that have failed in that way at the end of a boxing plate due to poor design. The point of boxing a Model A frame is to reduce flex. You're also typically expecting the boxing plates to support crossmembers and motor mounts, etc. If you don't fully weld the boxing plates, you have a lot of opportunity for flex and stress at the end of each weld joint, as the plate and frame can then move independently in these areas. ***uming the welds are done properly, welding the entire length will reduce the opportunity for crack initiation at the end points of the beads due to flex between them. Of course this ***umes that your welds aren't full of defects. However, I think the key here is that the original poster stated that he was thinking of not fully welding it because he's a novice. If you don't trust your ability to weld the full length, then you should put in a lot of practice before welding it at all. Weld defects are nothing to gamble with in something as important as your hot rod ch***is.
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