Bevel Edges?

[WookieWelding]

make sure to round the edges on your fish plates to prevent a crack from forming and running

[brucer]

At what thickness does it make sense to start beveling edges in order to get stellar penetration? I'm using 2"x4"x1/8" steel to build the chassis for my car and am curious if I should be beveling the edges at the mitered joints? Thanks guys.

the 73 chevy truck, the dodge d50, the half dozen s-10's, the 92 mustang, 27ford, 80 chevy truck that i have backhalved, mini tubbed,and built full chassis. i have always just used a 90deg. die grinder with a sanding disk on it and put probably a .60-.080 bevel on them... i usually run my mig welder pretty hot when i weld frame rails, but i like to get good penetration... i grind the chamfer on the pieces of tubing and i butt the 2 pieces together and weld them...

i use a lincoln 180c and i'm probably around 140-150 amps when i weld them..

adding this in... on street cars and trucks i usually use 3/16 wall tubing.. the extra weight makes a streetcar ride alot smoother... unless the customer requests different..

[SICFabrications]

wellis, on 1/8th material, i would not leave any gaps... fit up is going to be crucial. when you leave gaps, it WILL pull and draw on ya and youre not going to like the outcome... just sayin... i bevel anything thicker than 1/4 and i dont bevel all the way through unless using a backer bar.

insanity, im sorry, but i will disagree... you can not take a millermatic 140 and weld 2 inch thick material, regardless of the amount of passes... you will have too much cold lap and i doubt you would get the first passes to have even burned into the parent metal without some serious preheating... 140 amps just isnt enough. i wont recommend this method to anyone. now, were it a stick machine, that would be a different story. ive seen x-rays and tested welds both DT and NT and even old pros sometimes fail. you would not believe the amount of cold lapping a mig machine will produce if the machine isnt big enough to handle the job...

wellis, if you are uncertain as to whether you are getting enough penetration, brucer gave some good advice. make your cuts, then hit the edges with a grinder to make a 45 degree bevel along the edges and move along...

i'll say this, when i am building motorbike frames, i bevel the tubing, but i leave NO gaps anywhere... the best riding frames are the ones that can hold themselves together without a tack weld anywhere on them.... it all boils down to fit up prior to welding

---------- Post added at 05:01 PM ---------- Previous post was at 04:56 PM ----------

one last thing, your fish plates should NOT have any square or pointed edges anywhere..... it creates stress and will ultimately crack. round the corners, never sharp.... and the ends should not cross the parent railing, should look and terminate more like a rugby ball (which is a lil fatter and more blunt that a football)

[Gadget]

Ah, the things you can learn here if you pay attention. Thanks Stan.

[INSANITY]

I was being sacastic about the 2 inch plate but that was wrong of me when someone was asking a legitimate question! I apologize for that!

But this is why I joined this forum! Your Knowledge!

I know that everything I do is half assed at best!

This is a C Notch bridge setup that I did! It was tripple welded so that I could grind the welds smoth, skim coated with bondo and single stage painted!
This truck was rearended in 2009, HARD!It tacoed the bed but not one crack or chip at any joints! Then went on a frame rack and revealed nothing had moved!
Even I was in disbelief! I guess I did somthing right! lol

[INSANITY]

This is the set of drag blocks that I made for the same truck!
Made from forlift forks, 1 inch plate and 1/2 inch round bar to build up a front taper!

Welded with my little Lincoln, No bevels and a Slow Single Pass! Trust me they were stuck!

[SICFabrications]

insanity, i wasnt saying that to discredit your work, you really are an artist and turn out really nice stuff.

[INSANITY]

insanity, i wasnt saying that to discredit your work, you really are an artist and turn out really nice stuff.

Thanks for the compliment!
But you did make me realize that I'm not a fabricator - Yet!
I can make stuff but I have so much to learn, everything I know, I taught myself!
It's difficult to go to school without a teacher!
Although that would have made kindergarden through 12th grade WAY BETTER!

[tigqk]

If your doing say a frame section the way I was taught in school was to split the load on a straight section 60/40, no gap.At the low end of the thickness of steel their is no benifit to beveling.Some guys like 45, you can do it 37 deg.Can also bevel only one side and leave the other straight.

Automotive welding has gotten very strick, cannot heat any hi strength steels beyond dull red or you create a large HAZ ,making the grain fine on unicoupes, welds have to be a reproduction of original joining processes.

[Nick]

Insanity, could you do a drawing of the methods you talking about? Thanks

Charley, from the bike side of things. "Using a hot dog", slugging, or sleeving might sound more familiar.

Used to maximize and distribute the area handling the stress. On the motorcycle side, think internal. Thinner od tube/round bar inserted into the joint to overlap by ~2" on either side to allow a smoothly ground finished product with high strength once welded at the joint, and plug welded into the slug/hot dog. (An example - using thermal expansion/contraction to lock the slug and tubes together as they come down to room temp, giving you more structure to weld on. Or machining the round bar / smaller tube to be press fit or slide in)

Ferrari uses the process to fit valve guides/seats into their cylinder heads with a pair of robots called Romeo and Juliet. Valve guides are dipped in liquid nitrogen, cylinder heads are heated then pressed together. Once temperatures even out, you won't have much luck parting the two.

More to subject - Wellis, quite a few locost builders will bevel their tubing for frame construction. A lot of it in the .120" range. It comes down to your weld quality and consistency. Running a few scrap pieces in the same format as your finished piece and cutting them to check penetration would help assure you're on the right track.