I have a question I haven't seen dealt anywhere in any good way. How to know when your welds are good enough to hold safely for your intended use. I have seen videos on penetration (acid etch etc) as well as destructive testing on welds (BFH). But thats it. In my case I want to weld in a crossmember. But I don't want to do it if I'm not safe. Now I know there is a number of variables (one being liability), others being material, angles, penetration, intended use (onroad/offroad/racing, angles of workign joints ) so on and so on - which is perhaps why there is no hard and fast rule. However.... There are literally a 1000 threads on old timers/builders who literally state the following. "Grab a 6013/7018 rod and just drag it - I have welded many cars/trucks./frames like this and NEVER had a weld fail". versus when you join a true welding forum ..... " You are using 5% below the rated amperage for said thickness material ..... I wouldn't trust that weld" How do we join the two to get the true answer. As i believe neither answer is correct. And the truth as always is somewhere in between. Like to hear from people with real world experience welding on farms, hotrods, vehicles and machinery.
The only way to know for sure would be to have your work tested. Either NDT or destructive. There are standard processes for most welds. If you master the process then you should be confident in your welds.
If you have to ask, maybe you should think twice before experimenting on your current project. Get someone else to do the current welding while you bone up a little. It's a skill that can be learned. Just takes a little time and experience.
If you have to ask your welding probably isnt good enough. Also these forums tend to get really opinionated one way or the next and tend to cloud an issue even more than before you started to research it. Keep it simple, weld it up right if you can, if not take it to someone your confident that can. Leave all the science and debates to the guys who spend most of their time on the computer instead of actually building stuff.
X2 with gearheadbill's response : If you don't trust your own skills, find someone you DO trust to do it for you : you'll definitely sleep better at night!
I was self taught starting in the early '70's with both gas and arc. Got pretty fair with gas welding sheet metal for patch panels on my 5W and did 99% of the frame and suspension fabrication. Only had an AC welder and used a lot of 7014 rod, maybe there were better rod choices as far as tensile strength but I really don't know. I do know that the frame I boxed did not break even one weld when I struck a pole and folded a front frame horn down about 4 inches and in at least 45* in an accident. Those welds were ground and dressed for appearance too. I would advise practicing on the same thickness you intend to fabricate with. Get as comfortable as you can and have the material fitted well and any dirt or rust ground/sanded off. I think you will learn when you have the correct amperage and weld penetration. In general terms a good weld looks good but be mindful of the penetration. Some would laugh at my use of 7014, it is not an "all position rod" but not having a DC machine limited my choice and anyway doing a bare frame I could roll it around to whichever way suited my needs. It worked for me but your mileage may vary.
Fordors, 7014 is a great rod. It is a fast freeze rod so appearance may not always be to good. But for the guys that only have AC machines they should try 7018-AC. Runs just like the DC version.
Easy to say "if you have to ask etc" .........but I use an analogy in my work ...... I have a couple of guys who work for me who think they are the cats meow. But they don't know crap basically and are wrong more often than they are right. I'm pretty sure the same thing exists in all industry including fabrication. I've also seen welds by guys who claim to never had had a problem (by picture or in person). And they didn't look that good to me ...... even some from manufacturers pushing the limits on time/resources to get jobs out quick. Do the welds fail ultimately ? I dont know. I've only ever seen 1 or two cases documented in a forum where are weld failed it intended purpose. So whilst I get what you guys are saying ..... it ultimately just feeds into the original question of you probably don't know .... your just ok [or not ok] with your capabilities Not stirring the pot ......... its a serious Q. If the old timers are just "Grab the 6013 and let her RIP ......" ....... then as long as your bead profile looks ok ....... doesn't sound like people are experiencing many issues here
Good point ...... circles. Let me reword. I have destructive tested my welds (BFH) , acid etched profiled them to show penetration, and have spent time looking at both the root penetration and toe penetration. Now I'm onto comparing them between types of welding... mainly FCAW-S and SMAW. (6011/6013/7014). In all instances I feel Im getting closer to having a good profile that I would believe be better than a half of what I've read/seen from guys who don't do it for a living or regularly ........... like my uncle on the farm for example However he has never (nor I) welded a crossmember for a daily driver. Different. So - no point saying I'm confident in that application as I've never done it before ......... Im confident I've practiced those types of welds of the same thickness in the same position on some test material ..... but thats it. Someones always got to pop their cherry somewhere on this ........ so
You know readhead, now that I think about it I did use 7018, that's know as a low hydrogen rod, right? It was a long time ago, CRS. Sorry for the thread hi-jack.
Nope - no problems with rational discussion. 7018 is another consideration (after 7014). I know lots of guys use it - meant to be more flexible during stress.
I did just what he suggested when I lived in Texas and was building my T bucket. I had a little Monkey Wards welder that I could tack things together with and then haul them down the street to my buddy who welded it up right. If you do have a good welder in your shop it shouldn't be that hard to find someone who can finish the welding up after you have it all tacked together though. It is a lot easier to get someone to do it at your place using your electricity, your welder and your materials normally.
Angry or mad do not describe this Canadian. Just bored and not wanting to read or hear from any of the endless "experts" who post in these mostly useless threads. In my time on the Hamb I've learned that for the most part it is best to ignore these threads. Hence my attempt at sarcasm, which was obviously lost on you.
I have a decent 230V welder multiprocess. Am happy to keep working on my welds till I'm confident they are good. But like everything in life - you need feedback to develop that confidence - something to refer/compare to/from and educating yourself. So - hence the thread. There's a lot of BS out there. Weeding through it ..... eg Anyone here had a critical weld fail using a low penetration rod like 6013 ??? Wondering. eg Anyone done a comparison of 6013 (good weld) versus FCAW-S - and found a strength difference ? Most of the guys I talk to just put it in there Never heard of a failure.
I've been welding a long time and still don't consider myself to be a great welder. But it always holds well, good penetration and it has been tested-tough with stock car racing. Look at a car chassis... lots of welds that look like crap, but they're strong and will never fail if they haven't already. The last thing I welded was the motor mounts on my '59 Ford and I used 7018 rod and a Lincoln 225 amp welder. I practiced on some scrap since I was a tad rusty, but got good penetration with the actual mount welding. I find that most people tend to weld at too low an amperage and that causes them to struggle with it. An old timer told me that it has to sound like bacon and eggs in a pan... lol.
Thanks. Yup. Always remember this picture ...... welds look ok ... but hard to tell penetration as stacked on each other (would have to see at each run) http://www.weldingtipsandtricks.com/Mig-welding-tips.html bottom of page
In the industry I work in, we use details and redundancies that allow for variation in quality of work without sacrificing the design criteria required to meet minimums. In short... we over-engineer to make up for field *ahem* adjustments. This is necessary even when using certified weldors, who are human just like the rest of us. I take that same thought process into my car building, by adding a bit of weld length, a bit of extra section, or gusseting, etc. to what I design. This (hopefully) makes up for my "field adjustments". Now if I were building a race car or some form of performance design where every ounce mattered, this would be poor design. I'm not doing that. I'm just building a cruiser to drive around in. Is it the best solution? Probably not. Is it real-world forgiving? Yup.
Yet you took the time to open & read the comments and made the effort to post..........I guess I don't understand why when you can pass on by and ignore it.
Take a welding class at your JC. Once you get some practice you can tell whether you have a good weld going by watching the puddle. You instinctively know if the amperage is correct, your speed is correct, etc., and can hit the necessary penetration target every time. Notes on types of welders; wire feed welders are usually too low in amperage to give good penetration on anything thicker than 1/16" stock unless you spend a lot of money on a pro type unit. Also, the wire comes in typically one alloy and the welds tend to be very hard and brittle. Don't use these machines for frame work or any critical stressed parts. Get a good old Lincoln 225amp buzz box and you can select the proper rod for the job. Plus you have the power to get all the penetration you need for a pro job. And they aren't that expensive.
Since you are working on a crossmember installation, I would suggest designing your assembly so that the weld is not a single point failure. For example; if the frame is boxed, remove the boxing material so that you can insert the crossmember into the frame, weld it and box around it. Also consider bolting or riveting the crossmember into the frame. You can never be absolutely certain that your entire weld is perfect so fabricate your assemblies with that in mind.
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