Most people at some point want to build/fab some kind of metal armor for there trucks. Front bumpers, racks, sliders, skid plates, rear bumpers, light bars. ANYTHING!!!

If someone could go over basic welding rules and techniques, feel free to share any info that will contribute to successful welding!!



FAQ and ANSWERS!!!

1. What of steel to use for bumpers?
2. What metals weld (stick) together?
3. What kind of welders to use?
4. How thick of tube for bumpers??
5. Does it have to be bare metal for a good weld?

continue...

 

 

I'm by no means an expert, but I've taken a couple classes so I'll answer the best I can. For much better information, I'd suggest going over to a forum like http://www.offroadfabnet.com/.

1. What of steel to use for bumpers?

Carbon Steel is the standard I believe for most stuff. If you go to your local metal job and ask for plate, it'll probably be carbon (I think, someone correct me if I'm wrong). But to answer your question, it depends on what your looking to. I mean if you want to build a PreRunner tube bumper, go with something like 1.75" (.120 or thicker) DOM Tube. Probably need a bender of some sort to make it look decent though.

If you just want to build a big honkin' no-one-will-ever-damage-this bumper, go with plate. 1/8" will probably work. 1/4" would be beefy. 3/8" would be really strong. It'll be heavy as hell if it's normal size, but we need to be more specific to know what your looking for.

I mean you could even go with Chromoly stuff or something if you just had money to spend, but that kind of stuff would better be spent on frames in my opinion and wouldn't be worth dropping the $$$ on for a bumper.

2. What metals weld (stick) together?

All kinds? It doesn't really make sense. You can weld anything. Hell you can weld plastic (it's not really the same process but they call it welding). Obviously some metals like Chromoly and Aluminum are a bit more picky and to really weld them well, you need to be good at TIG welding. But any type of steel you can MIG. And with the right setup, you can MIG aluminum and Chromoly but you have to be damn good and know what your doing, so I wouldn't recommend it if your new to welding. Stick with standard Carbon Steel with a Wire Feed MIG.

If you don't know, TIG stands for Tungsten Inert Gas and MIG stands for Metal Inert Gas. Sometimes they are referred to as GTAW (Gas Tungsten Arc Welding) or GMAW (Gas Metal Arc Welding). MIG is a much easier process to learn, is very quick, but has less applications to due to inability to have fine control over the weld. TIG on the other hand is much harder to get good at, takes much longer, but you can finely control the puddle which allows for much higher quality welds. For more information, I'd just hit up google for awhile.

3. What kind of welders to use?

If your first learning, pick up a MIG. 220V Welders will get you way better quality welds then a Home Depot special. But those Home Depot welders definitely have there place. If you are doing light duty welding, then a small 120V will work fine. Especially considering the price tag on a good 220V welder.

4. How thick of tube for bumpers??

It depends on application. I mean go measure the bumper that's on your truck right now. That metal is probably only 1/8" thick if that. .120 (Tube standard thickness is done in decimal form) would work. That's pretty much the standard. Rollcages get made out of .120 so it'll work for bumpers. If your worried about hitting a lot of stuff, go with something a little thicker. It'll weigh more, but you'll repair it less.

5. Does it have to be bare metal for a good weld?

If you want your welds to be really clean and look professional, yes! Clean your metal. Make sure that all those oils and rust and other crap is all cleaned off. It'll make your welds so much better. This was the first lesson I learned in my classes and it's one I won't forget. If you have spare metal lying around, try welding a rusty piece of steel, followed by a nice clean freshly ground piece of steel. World of difference in the quality of your puddle and the ability to control it.

 

Matt pretty well hit the nail on the head.

1. Carbon steel is what bumpers are made from 99% of the time. In my opinion, don't waste DOM tube on a bumper unless it's tied into a roll cage of some sort or you've got cash to burn. HREW or CREW (hot-or-cold rolled electric welded) tube will suffice and is much cheaper. As far as plate steel, if you make a bumper out of 3/8" plate you'll need a forklift to mount it and your truck will look like a dragster going down the road! Most people (for a road-armor style bumper) will use 10ga sheet, 1/8" plate, or 3/16" plate. 1/4" would be outrageously beefy IMO. You'd be very hard pressed to do any damage to that without obliterating your truck.

2. As far as what kinds of metals stick together, you'd have to really know your metallurgy to get an answer like you want, I think. I've taken some time to study, but I don't want to tell you any wrong information. The basics though, for anything you'd ever want to weld, is that you can't weld aluminum to steel. Well, you CAN, but it wouldn't be very strong, so it would be best not to do it. Beyond that, there are things to know like you need nickel rod to weld cast iron, but seriously who uses cast iron anyways?

3. Every welder has its ups and downs. Most people use a wirefeed welder in any number of configurations for its ease and simplicity. A wirefeed welder can weld steel with flux-core wire or inert gas, and it can weld aluminum with an aluminum spool gun and argon gas. A GTAW (most people know it as TIG, but that's the wrong term nowadays) welder can weld either steel or aluminum. It's a much more complicated machine to set properly and the technique is also very difficult. There are also stick, arc, or SMAW welders which burn a welding electrode that is covered in flux. These are very simple welders as well which can be very versatile due to the number of different electrodes available. They can be tricky to use sometimes though because the electrode continues to get shorter as it gets burnt off. You can also get into oxy-acetylene welding too, but generally there isn't much incentive anymore to use that over a GMAW (MIG) or GTAW (TIG) welder.

4. Truthfully, either .095 wall or .120 wall will suffice. I prefer 1.5" diameter for smaller trucks, and 1.75" for larger trucks, but that's as much an aesthetics thing as a strength thing. .120 wall tube is easy to find and would for for a bumper in either tube diameter.

5. While it's not as critical in stick or Flux-core welding, cleaning your welds before AND after is ALWAYS good practice, and is absolutely critical when welding aluminum and GTAW welding. Steel is sold with "scale" on it, which basically protects the metal from rust and such. Taking that off with a wire brush, grinder, or even a scotch-brite pad, will give you cleaner, better-looking, stronger welds. Always do it.

If you want to learn, go and take a class! It's very difficult to understand proper welding techniques if you have to discover them on your own. Take a class or have a very good friend who has taken a class teach you. It's important to understand the proper settings and procedures for welding, watching the weld puddle, and all that. If you don't learn them properly, your welds might look good, but they won't have good penetration or could be cold and more likely to break. Strength and good technique come first, and pretty welds come second!