Chevrolet Nova Forum banner
1 - 14 of 14 Posts

·
Registered
Joined
·
938 Posts
Discussion Starter · #1 ·
I recently got an Arc welder for welding thicker metal together. I just got it wired up today and started playing with it. I was playing around trying to weld a 3/16" wall 2.5" diameter pipe to a 1/4" wall 3" piece of square tubing. (just using some scrap I have laying around) The first time I did it things looked OK then I decided to really test it out so I got a claw hammer and started striking it to see if it would seperate. After 4 strikes sure enough the weld broke. So I flip the pipe over (clean end) and weld it to a different place on the square tubing. This time I struck it about a dozen times as hard as I could and it did not brake. So I moved up and welded two 3" square 1/4" thick wall pieces together in a "T" and beat the heck out of it to see if it would brake. It didn't brake so I am assuming this means I have solid welds. While I'm new to Arc welding and my beeds are not the best looking it seems they are strong. Is their some other way I should test the strength of my welds?

By the way I am welding using the DC part of the arc welder with 3/32" rod. The welder is around 80 Amps and it takes me 2-3 passes to get a good fill in my chamfers, and I am cleaning up the weld in between passes.
 

·
Registered
Joined
·
116 Posts
You need a bigger hammer! lmao Actually, if you knocked it apart with a 16 oz hammer, it wasnt welded very good. If you wanna hammer-test it, you should use a 2 or 3 lb sledge. But the best way to make sure youre getting penetration would be to lay a couple of pieces of 1/4" plate flat and weld them together and that way you can inspect it from the backside to see how deep it penetrated. :thumbsup:
 

·
Registered
Joined
·
938 Posts
Discussion Starter · #3 ·
I don't have any 1/4" scrap flat stock laying around, but I do have a couple pieces of 1/2"! Maybe I'll deep chamfer both sides and see if the weld from one side makes it to the other on it. If I can get good penetration on 1/2" then I should be doing fine when it comes to my intended project which is made of 3/16" wall square tubing. If the 1/2" test doesn't seem to work I'll have to wait until the 2nd and then go to work and dig through the scrap metal bin and see what the fabricators have disgarded. I'm building a car rotissiery, so I want to make sure my welds are good before I start on it. Don't want to have it give out on me and drop my Nova on me! Might damage the Nova!:eek:
 

·
Registered
Joined
·
116 Posts
Thats a BIG 10-4! Theres a couple of stress points on a rotisserie that are EXTREMELY CRITICAL to be able to withstand a lotta force. Didnt I send you some sketches of rotisserie parts with the important spots on it? If not, I can. The 1/2" would be even better to practice on. Maybe even try welding a piece of 3/16 to the half. But when you make the rotisserie, you definitely need to make sure the stress points are very strong, cuz they really do have a large amount of force exerted on them...more than you would think. ;)
 

·
Registered
Joined
·
938 Posts
Discussion Starter · #5 ·
I did a little more playing around today. My nieghbor had some scrap 1/4" pieces so I used them to practice. I figured out that if you use a jumper cable between the two pieces you are welding you get better penatration on both pieces also if you leave a small gap (1/32" to 1/16") between the pieces before you start the weld makes it the whole way through. I end up using more rod, but the weld definately looks stronger! It also makes it 3 to 4 passes to completely finish a weld. Also my beeds are looking better every time I make a practice pass.:)

I don't think I got anything from you on the stress points. This site has the plans I am using, http://www.harwoodperformance.bizland.com/1941buick/Editorial_20.htm .
I am making a couple of small alterations such as the rotating sleeve has been bumped up to 1/4" thick wall and I had the machine shop at work machine a 1/16" off the outside diameter of the pin but also it went up to 1/2" wall thickness. I will have the pin welded to the arm by a professional at work since I see that as the largest stress point!
 

·
Registered
Joined
·
116 Posts
Otay, heres where you need to make SURE its strong.
#1 has an enormous amount of force exerted on it but not in the direction which he has it reinforced...the gussets in the #2 area would be in the right direction...think of it as the weight of the car exerting pressure on a cheater bar twisting a bolt where that weld is...of the whole rotisserie, this is by far the most stressed point...0-10, its a 10 :D
#2 and 3 both are under a load in the same direction as #1, but not near as much...0-10, theyre both 6s


Dont get me wrong, cuz in all actuality, it doesnt take much to hold up a unibody car, especially if its pure downward force. The problem is, its usually not. For example, before I built my rotisserie, I had the rear of my car supported by two stands I made using 1" x 1" steel tubing, and they were 3' tall, basically a 3 foot piece of tubing on each side. Looking at it would scare ya, but the fact that it was simply straight up and down allowed it to hold my car up for a few weeks, even though my wife thought I was bonkers. Anyways, my point is, those 3 areas need to be very strong, as they are the most likely to fail, and we dont want that to happen!

P.S. Which "pin" are you referring to?
 

·
Registered
Joined
·
938 Posts
Discussion Starter · #7 ·
The Pin I am referring to is the actual rotating tube that goes into the sleeve. Do the gussets you added in area #1 allow you to still get it high enough to match center of gravity? If it does how far up do you take them? I am thinking you could strengthen area #1 using triangles on the face and back side basically sandwiching the #1 stress joint between them. In addition to welding these bolts could be added for extra strength and to reassure the amature welder.

At joint #3 some small gussets could be added to the bottom of the sleeve and the support post. Also a strap of 1/8" steel could be bent to go over the sleeve in a "U" shaped then bolts put through the support and the ends of the "U" in addition to welding.

At joint #2 the gussets will only help support as long as the car is in the first position or completely upside down. You just have to weld this really well!
 

·
Registered
Joined
·
116 Posts
Yes, youre on the right track about the #1 area...thats what I was thinking could be done also, as well as welding the cross-bar to the front side of the downward brace instead of on the end. I dont think a strap would be necessary for #3 area, just a good weld. To be honest, the way that ones made and the materials used are plenty heavy enough to support a full car, its actually overkill IMO. I was just pointing out that those areas will be the weak links in the chain and need the most attention. If ya go look at mine on my website, youll see how lightweight it is...the whole thing was made with roughly 35' of 2 x 2 x 1/8 steel tubing and 20' of 1 x 1 tubing for braces and it was plenty stout enough to hold my car for 2 years as a rotisserie and is still supporting it now as a roll-around car stand while assembling and painting etc. (I just chopped the rotator sleeves off, added casters, and welded them together ;) )
 

·
Registered
Joined
·
938 Posts
Discussion Starter · #9 ·
I got 3 X 3 square with 3/16" wall and 2.5" X 2.5" square with 3/16" wall for building mine. I plan on keeping it around and pass it around the family. Once I'm done with my Nova my brother will probably use it on his 66 Impala. Then I will probably take it back and use it on a 63 Impala SS convertable. So as you can tell this thing is going to need a long life span and be able to support heavy car bodies! Most of my gusset steel is 1/4" plate and I've got a couple pieces of 1/2" for critical areas. Later on I'm looking into building a motor and adjustable drive shaft across the bottom, then using chains to turn both ends at the time and rate so it will auto rotate. That all will be after I finish this stage and find out how hard it is for one man to rotate!
 

·
Registered
Joined
·
116 Posts
How easy it rotates depends on how balanced ya get it. Since that one is adjustable, you should be able to get it very close. When balanced, its very easy for one person to spin it around...the hardest part is getting it up in the air lol.
 

·
Registered
Joined
·
361 Posts
If you really want really strong welds try ER7018 on reverse polarity it comes in 3/32 , the reverse polarity really burns in and penetrates . Are you using 6011 right now?
 

·
Registered
Joined
·
938 Posts
Discussion Starter · #12 ·
Right now I'm using E6013 3/32" x 12" By Lincoln Electric. Also using the recommended DC polarity from the instruction booklet that came with my Chicago AC/DC stick welder. The welding rod numbering confuses the heck out of me, so I just told the guy at the store what I was welding and asked what I should use. I've had no training in using a welder. Everything I've learned I learned by trial and error. I'll have to look into the ER7018 rods and give them a try and see how things turn out! Thanks!
 

·
Premium Member
Joined
·
17,540 Posts
Check out your local school district adult vocational education classes (next to free) as they can get you schooled in the basics. Laying down a good bead comes with practice, knowing the correct amperage to use with what stick is cheapest if learned from a book with an instructor. Hard knocks is of course the best way to learn but it is expensive, and takes a little while longer.


Big Dave
 

·
Registered
Joined
·
938 Posts
Discussion Starter · #14 ·
I want to take a class, but with my line of work I'm lucky to be home for 2 weeks straight in a row. Most classes are set up over a couple of months. I would be lucky to make it to 1/3 of the classes and would probably fall behind really quickly. Maybe I could send the wife and then she could teach me! Not, as she won't even set foot in my garage.
 
1 - 14 of 14 Posts
Top