Welding Tips and Tricks

Ok I am looking to build my own 6x10 utility trailer. Base frame will be made from L-angle. I was watching Jody's videos on planning your welds to help prevent distortion. I was wondering if I lay the rectangle frame, tack it up and lay the cross pieces and tack it up and then weld everything would I still have to worry about distortion even though I have a bunch of pieces tacked up?

You can get distortion in the "vertical" axis I addition to the "horizontal" axis. Clamping and tacking helps a great deal, but heat effects steel in a myriad of ways. Adding more angles, bracing and minimizing how long you weld in any one place is the trick. There's no formula for it, you just need to be patient and keep measuring as you go.

Also, because it's a trailer and not a tight tolerance, machined piece, you can withstand some amount of skewing without losing your objective. But if you watch a chassis builder, they move around constantly and almost never wrap a single tube with weld unless the entire structure is clamped tight and held in place until cooled.

Ok yeah I planned on moving around a lot and it's not critical tolerances just figured if I'm going to "practice" I mine as well practice the correct way. I'll just watch his videos again and try to stick to the weld pattern.

Not to kill the buzz but using angle for a trailer has proven to be weak in my experience. Often see twisted frame tongues especially due to the fact that angle can be bent in two more axis than a square tubing. I would use square for a trailer.

bruce991 wrote:Not to kill the buzz but using angle for a trailer has proven to be weak in my experience. Often see twisted frame tongues especially due to the fact that angle can be bent in two more axis than a square tubing. I would use square for a trailer.

For that size of trailer id say it would be fine as long as you aren't hauling massive loads of sheet rock or metal at 70miles an hour all the time. Just don't overload it.

Farmwelding wrote:

bruce991 wrote:Not to kill the buzz but using angle for a trailer has proven to be weak in my experience. Often see twisted frame tongues especially due to the fact that angle can be bent in two more axis than a square tubing. I would use square for a trailer.

For that size of trailer id say it would be fine as long as you aren't hauling massive loads of sheet rock or metal at 70miles an hour all the time. Just don't overload it.

C channel works great for trailer frames. I see L and angle built trailers all the time and they hold up fine if not abused. I have done a lot of repairs on trailers and the number 1 thing I see is de-arched axles and broken leafs but not really any frame damage unless it was in an accident.

Had neighbor come over with his trailer it has L angle frame and tongue and he loaned it out. Person tried to drive a Kubota up on to it (this was 2 inch by 2 inch L channel frame and tongue), when front end of tractor approached back of trailer the tongue bent immediately as it tried to reach for the sky, (stupid to try without jacks under rear of course) and the back of the trailer headed down. Way under built for a trailer big enough for a tractor and implement with two axles. Saw another where in backing up they jacked the trailer a bit to far and tongue took a small side load from the bumper, and folded up like sheet metal. Guess if your only hauling some small things and never loan it out you may be okay.

Farmwelding wrote:

bruce991 wrote:Not to kill the buzz but using angle for a trailer has proven to be weak in my experience. Often see twisted frame tongues especially due to the fact that angle can be bent in two more axis than a square tubing. I would use square for a trailer.

For that size of trailer id say it would be fine as long as you aren't hauling massive loads of sheet rock or metal at 70miles an hour all the time. Just don't overload it.

Farmwelding - what are you basing your decision off of? You do not know what leg size or thickness he plans to use, the weight rating he wants, single or double axle, overall design of the trailer, type of reinforcement in critical areas (if any are even planned) - nothing.

C channel or square/rectangle tubing are superior trailer materials. I lean toward C channel here in the salted road rust belt.

@Pavetim - yes, you do still have to think about distortion. Watch the heck out of those videos (I still learn stuff from his videos every week), plan your welds accordingly.

exnailpounder wrote: C channel works great for trailer frames. I see L and angle built trailers all the time and they hold up fine if not abused. I have done a lot of repairs on trailers and the number 1 thing I see is de-arched axles and broken leafs but not really any frame damage unless it was in an accident.

I'm a fan of C channel for frames myself.
Would prefer square/rectangle but traps too much moisture here and rusts out from the inside.
Repaired some with rust through problems that were way too early in their life span.
Seen many channel frames with surface rust only after 20+ years.

Worked on bobcat trailers that had huge angle for the side rails - worked really well and the axles failed first like you said.
A nice "smile" is not good for axles

Most I will have on it would be say 1500 lbs and that would be the absolute max. I have C channel for the tongue part, i'm doing the triangle tongue and not the straight style. I'm using 2x2, 3/16" L angle for the frame and 7 cross members of the same L angle. I agree C channel would be superior but for what i'm using it for this should be plenty strong enough. Oh i'm also doing "railings" and thats out of 2x2 square tubing 3/16".

MinnesotaDave wrote: Would prefer square/rectangle but traps too much moisture here and rusts out from the inside.

I noticed that when I rewired my horse trailer. I drilled a few drain holes on the bottom surface and a few along the neutral axis on the side. I figured that would not only allow the water to drain, but get some air flow through there to dry out the condensation. I have no idea if that actually helped because it also introduces another way for water to enter, but it seemed like there was already a way for the water to get in, there just wasn't any way for it to get out. Around here in the winter there's more salt on the roads than snow.

Funny to hear about rotting out. My trailer was built in 1969 yes 1969 and sat outside and is still in fine shape. The corners are not mitered though so air flows through the frame easily allowing no water entrapment. But is a place wasps like to migrate, so I recently put plastic plugs in the four corners.

bruce991 wrote:Funny to hear about rotting out. My trailer was built in 1969 yes 1969 and sat outside and is still in fine shape. The corners are not mitered though so air flows through the frame easily allowing no water entrapment. But is a place wasps like to migrate, so I recently put plastic plugs in the four corners.

I hear you there.
I was welding on a trailer and bees came out of an open end just like you describe - almost right into my face.

Fortunately the cutting torch was laying next to me - they did not survive the heat that blew through that tube

MarkL wrote:

MinnesotaDave wrote: Would prefer square/rectangle but traps too much moisture here and rusts out from the inside.

I noticed that when I rewired my horse trailer. I drilled a few drain holes on the bottom surface and a few along the neutral axis on the side. I figured that would not only allow the water to drain, but get some air flow through there to dry out the condensation. I have no idea if that actually helped because it also introduces another way for water to enter, but it seemed like there was already a way for the water to get in, there just wasn't any way for it to get out. Around here in the winter there's more salt on the roads than snow.

I hear you Mark. I have never really seen any angle trailers rust out other than surface rust. I have done some repairs on aluminum trailers that are pitted beyond belief though. Steel will hold up well if its allowed to shed water and dry out. I just wish I could find paint that will stay on a trailer. My 2011 16 footer looks like its 20 years old and has barely been used.

MinnesotaDave wrote:

bruce991 wrote:Funny to hear about rotting out. My trailer was built in 1969 yes 1969 and sat outside and is still in fine shape. The corners are not mitered though so air flows through the frame easily allowing no water entrapment. But is a place wasps like to migrate, so I recently put plastic plugs in the four corners.

I hear you there.
I was welding on a trailer and bees came out of an open end just like you describe - almost right into my face.

Fortunately the cutting torch was laying next to me - they did not survive the heat that blew through that tube

It's amazing how well those bees will find tiny holes in trailers. A little brake cleaner or ether does the trick. Moral of the story-don't leave open holes on your trailer.

This past year I got stung on back of hand as I rolled trailer up to car, they hit me so fast I couldn't believe it and had bad reaction and swelling for days. Next time I had to use trailer I sprayed some wasp spray in frame and waited, thought all clear grabbed coupler and damn nest in tongue area they got me again on back of other arm.

Ok forgive the noob questions but that's what I am lol. For the trailer, like I said it's 3/16 mild steel. The miller calculator says 3/32 tungsten which I have, says 190-200 amps but that seems like ALOT. It says inverter tigs req's less heat but how much, I have an inverter tig. It calls for 1/8 filler too and again that seems awefully thick. I'll play around with some scraps first, just wanted your guys opinions before I start here is what I figure i'll start with.

17 series air cooled WP torch
3/32 2% Thoriated tungsten sharpened to point
1/8 ER70S-2 filler rod
170 amps running foot switch.

A rough way to estimate amperage is 1 amp for a thousandth of thickness-up to a point. 3/16 is .1875 so that is about right. Just play with the pedal. Filler rod needs to be about that size because any smaller and you are forced to shove ike twice the amount of filler in each time.

Are you running a gap or a bevel at the welds? I'd recommend starting out between 120-150 amps with a 1/8 tungsten and a 3/32 filler. You will find if you have a gap you might need 1/8 filler.

Poland308 wrote:Are you running a gap or a bevel at the welds? I'd recommend starting out between 120-150 amps with a 1/8 tungsten and a 3/32 filler. You will find if you have a gap you might need 1/8 filler.

I like this approach also. If there's a gap, I'd rather weld from both sides with 3/32 than jam 1/8 in. Too heavy a filler and you are prone to not getting good tie ins. And, its more likely to trap a pocket of air. Just my $0.008 (accounting for currency exchange rates).

pavetim wrote:Ok forgive the noob questions but that's what I am lol. For the trailer, like I said it's 3/16 mild steel. The miller calculator says 3/32 tungsten which I have, says 190-200 amps but that seems like ALOT. It says inverter tigs req's less heat but how much, I have an inverter tig. It calls for 1/8 filler too and again that seems awefully thick. I'll play around with some scraps first, just wanted your guys opinions before I start here is what I figure i'll start with.

17 series air cooled WP torch
3/32 2% Thoriated tungsten sharpened to point
1/8 ER70S-2 filler rod
170 amps running foot switch.

In my experience it depends what you are doing.

For example, I was tig welding 3/16" "t" joint today showing a student what to do.
I ran 160 amps because that's all that machine has. I would have run more like 180-190 on the other machine.

These adjustments just get done based on experience and personal taste. The student found 160 amps to be just right for his abilities because he could go slower.

I used 1/16" filler because that's all we have at the school right now - works fine but 3/32" filler would have been nice too.

With a gap I would have liked 150-160 amps - or less depending on the gap and bevel.

Why weld the trailer with tig when stick would be faster?

And of course the obvious question for me is, if you're a noob, why are you building a trailer?

Miller recommended amps is for a full penetration weld in one pass for the specified parent thickness. If you have a vee preparation and intend to do two passes then you would halve the amps approximately.

As for paint, this is apparently the best stuff on the market. Its apparently tough as anything.

http://www.por15.com/POR-15_Rust_Preventive_Coating

Mick

Yeah I was going to use Por 15 anyways I have it. I'm practicing now, not actually just jumping into the trailer but that's my end project. Never really though about the bevel and gap I was just going to Mitre 45 degree angles for the outside frame and weld but the option of gap and bevel and welding both sides that's an option too.

Oh crap guess I forgot how thick my stuff was just measured the l angle and its 1/4 steel and not 3/16. Oops now my 210 everlast isn't strong enough