Learn to weld aluminum properly - where?

NVCC: Northern Virginia Community College, Manassas Campus has a welding ciriculum Wanted to go but never could make it work with my schedule..... Michelle

aluminum MIG would probably be easiest and best for building trailers.Very easy to learn to MIG(wire) weld.

Hi Karl:

Without veering off to far into the fear mongering that sometimes goes on here about trailers being built by guys new to welding, I can offer you this. If you don't already have a machine, then you are going to need something capable of at least 250 amps for most structural shapes. Being AL you are going to have to go thicker than you would think with steel. Most suitable channels and S shapes in AL are going to be 1/4 on the flanges and

3/16 web. This would be minimum IMHO. I have built or been involved in around 200 boats and have also built a few trailers for aforementioned boats, both AL and steel. One thing you will want to think about is gussetting (lots, min 3/16 plate) as AL will fatigue way quicker than steel when it is worked. (and it 'will' be in a trailer app.)

Now the fearmongering: If you are going to consider selling these trailers, also consider liability insurance. If you are wise, you will get it. If not you will gamble everything. While aluminum mig welding is easy to learn, it is even easier to put in a good looking bead that isn't worth shit, especially in the flat position. Flat is commonly mistaken as the easiest position to weld in, but in my mind it is the most difficult to put in an effective, sound weld. I have seen and repaired this on many (also read countless) different builders boats, dumptruck boxes, horse trailers, etc, etc. The list goes on and on. Many of these have been on supposedly reputable builders/manufacturers, some of them even carry certification of welding operations. It makes me shudder everytime one of these pieces of shit comes into the shop. It also makes me want to wear a helmet on the highways.

Take a course, or find a competent certified welder to teach you. I would even be a bit leery of most community college hobby courses regarding AL, unless the instructor is certified. I am sure that AWS certifies welders to AL procedures in the states as in Canada we are certified by the CWB and they pretty much piggyback AWS. Once you get some gun time under your belt start breaking your welds open to see what is going on inside. Once you are sure that every weld you put in is good then start building your trailers.

Best of luck and best wishes, this is just my .02!

Drew McEachren Journeyman Welder CWB all position certifications for AL MIG, Steel SMAW, FCAW, MIG

My welding background is similar to yours. I have just taken a stick welding course at the local community college, and am currently taking the MIG course. The instructor has many years professional experience, is knowledgable and is able to communicate his knowledge. The course provides the necessary background theory, someone who can critique my work and correct my mistakes, and an opportunity to become familiar with the capabilities of different types of equipment so that I'll have some clues before I lay out $ for my own.

However.... my impression is that like playing a musical instrument, writing software, marriage, and so many other things in life, you learn welding by 1) getting a good grounding in theory, 2) learning to recognize good and poor results when you see them, and then 3) practice, practice, practice for the rest of your life. The sooner you make your first 1000 mistakes, the sooner they'll be behind you.

Good luck. Mickey

Drew -

Thanks for the thoughtful reply. Very helpful.

I assumed I would have to work with some fairly thick stock, which is why I mentioned the trailer application. The trailers I plan to make are for fairly light sailing boats, but the design involves cantilevered c-arms to support the upper deck of a two-boat trailer, so some sort of really beefy gussetted Al channel is probably in order. Fortunately, a good friend is a mechanical engineer, so I'm more concerned about the execution than the design.

First trailers will be for personal use/abuse, not sale, so liability is not immediate concern - just the wellbeing of the boats, which being handmade one-offs is important enough to want to get there in one piece! I like the destructive testing idea - I know someone who can do that for me.

250 Amps is a LOT of amps! Need to check my breakers...

I will look for a course taught by someone AWS certified in Al. Seems like there were some week-long courses offered at various welding schools around the country - can't remember where, though. Was hoping someone on the list had taken one or more and could recommend for/against.

Is there a Bible on Al welding that I could read for a solid conceptual background?

Thanks Again, Karl

Drew McEachren wrote:

As far as how many amps, this is my opinion.

I just bought a Hobart Handler 180. As far as Aluminun goes, it could probably do 1/8" aluminum at the most. And 1/4" steel.

However, if you buy a 210 model from Hobart or Miller, both of those say they can do up to 1/4" Aluminum. These pull about 25 - 27 amps, depending on which brand you get. So you should run these from a 40amp breaker.

If you step up to a 250 or 251 model, then yes it could do thicker than

1/4" aluminum up to 3/8", but you will have to run this from a 50 or 60 amp breaker, depending on whether it's Hobart or Miller, they draw a little different amperage.

So if you expect to do alot of 3/16" Aluminum up to 1/4" you probably would be ok with the 210 models. If you need to do any thicker, then you would need a 250 or 251 model.

Drew's comments are spot on re aluminum. I am wondering at the choice of materials. Aluminum is not a very strong and has rigidity problems. In most cases aluminum welds are not as strong as the parent metal unlike steel welds. The location and size of an aluminum weld is critical. If it is corrosion you are concerned about I suggest using thin walled steel tubing then getting it hot dipped galvanized. If aluminum was practical for boat trailers you would see them on the market. What you do see are galvanized steel trailers. Randy

I would like to learn to weld aluminum, and I am looking for a place in Northern Virginia or Baltimore to take a class. I had some experience gas welding steel as a kid, but have no real knowledge of any other type of welding, and no formal education in welding. Apart from the simple pleasure of learning how to weld better, I would like to obtain enough proficiency to be able to reliably weld structural aluminum frames for small boat trailers, and sell them without worrying about them falling apart at the seams.

Any thoughts on where and how (i.e. what sequence of courses to take) to get a solid foundation in this arena would be appreciated. I would prefer an arrangement where I can learn at my own rate (i.e. quickly if I want to put in a lot of time) and I would even pay someone to spend time with me one on one if I could find a knowledgable person willing to do that.

TIA - Karl

most boat trailers here in florida are alum. at least the good ones, but all the axles, cross members are bolt on to the i beams.....

Just because you personally are using your homebuilt trailer will not relieve you of liability. Check with your home and auto insurance companies.

There are lost of trailer plans (designed or at least signed off by a PE) - I think Northern Tool and Supply has them. Maybe even make yourself a small utility trailer out of steel for first effort.

Take classes, read everything you can find, watch other welders, hire a tutor and practice, practice, practice.

Good luck

Thanks to everyone who responded.

I have been checking around and have found some attractive one-week courses offered by Lincoln in TIG and/or MIG welding that sound like they might be a solid way to start. Would make a nice one or two week vacation.

Appreciate concerns re: insurance and appropriateness of material choice. Capacity of trailers is quite small; ~800lb max load with two boats and gear. Steel utility trailer frame with lumber racks on top would be the cheapest way to get the job done - it's what we use now. But there are aluminum trailers on the market and they are much easier to wheel around when not attached to vehicle, and they tend to last longer and look better. There is ample precedent in heavier applications - if semi trucks can haul on aluminum gear, I should be able to make something that reliably takes 800lb. Plan to bolt on a torsion axle.

In the end, making a trailer like this is just an excuse for me to learn to weld aluminum. I would like to progress beyond that in MIG or TIG to stainless, titanium etc eventually, but one has to begin somewhere and this seemed an attainable goal. I am aware that there are cheaper and potentially more reliable ways to haul boats around.

Thanks again to all. Any thoughts on the best TIG setup for this application would be welcome.

Rgds, Karl

snipped-for-privacy@earthl> Just because you personally are using your homebuilt trailer will not