1/4 inch mild steel weld both sides?

[scolliflower]

I've been welding as a hobby for the last year and am now in the process of welding a trailer together (with the aid of purchased plans). My question might be ridiculous, but I thought I should be safe rather than sorry.

My plans call for 2" angle iron cross members to be welded to the 4" outside iron upside down. This allows wood to eventually be bolted to the cross members. My question is, should I fillet weld both sides of the 1/4" cross members or just one side for maximum strength?

I hope I'm describing the situation sufficiently. Let me know if you need more detail to answer.

 

[Welderpaul]

Always weld both sides where possible. It forms a much stronger joint than a one sided welded joint.

Welcome to the forum

 

[F.J.]

With it being 1/4" then it's obviously going to be a substantial trailer. Weld it all around to ensure the weight you put on it is safe. Dont forget pictures in the projects section

F.J.

 

[BrokenBiker]

weld both sides any chance you get. If you have access to it, weld it.

 

[Tman]

Can't go wrong with bit overkill on any structural welds both sides if accessible

 

[Fastfingaz]

Can't go wrong with bit overkill on any structural welds both sides if accessible

ofcourse,, the weld all around if posible holds true in all instences!!! but theres still another consideration,,, corosion factor!!! I'm sure you'll eventually want to paint this trailer so that means you won't be able to paint between the two angle you didn't weld, so there you'll have the beginning of rust and corosion, so it's better to weld so you can paint over it and minimize that problem,,,,,,IMHO

 

[scolliflower]

Good points about strength and paint! Thanks.

 

[jedmand]

What size trailer are you building and hows the progress going on it i am building a 6x4 trailer atm built out of built out of 50x50x3 box section got all the frame welded just need to do the sides the box part

 

[Liquid Metal]

I really dont mean to sound like an ****hole, but if you need to ask this, do you really think you should be building a trailer in the first place??? Also will the welding be inspected by a third party, as might need to be for insurance purposes.

 

[brightspark]

I really dont mean to sound like an ****hole, but if you need to ask this, do you really think you should be building a trailer in the first place??? Also will the welding be inspected by a third party, as might need to be for insurance purposes.

have a look here the welds look good enough 4 me http://www.mig-welding.co.uk/forum/threads/6-1-2-ft-x-18-ft-trailer.46173/#post-512456

 

[BrokenBiker]

he who does not ask, will never know.

its the only way to learn, and as said above, nowt wrong with the welds, just a bit of a moment where guidance was needed, which in sure happens to everyone.

 

[Liquid Metal]

Fair enough, like i said i wasnt having a pop at the guy, all i was getting at was "looks ok to me" isnt good enough for roadgoing trailers amongst lots of other things, especially when mig welding is involved as the process is notorious for lack of fusion defects where a weld might look perfect but the root and sidewalls arent fused properly.
The guy was asking if he needs to weld both sides, so wasnt sure. Would you want to be driving behind somebody towing trailer on a motorway at 60mph who was unsure of what they were doing when they made it???
Wasnt being nasty at all.

 

[brightspark]

Fair enough, like i said i wasnt having a pop at the guy, all i was getting at was "looks ok to me" isnt good enough for roadgoing trailers amongst lots of other things, especially when mig welding is involved as the process is notorious for lack of fusion defects where a weld might look perfect but the root and sidewalls arent fused properly.
The guy was asking if he needs to weld both sides, so wasnt sure. Would you want to be driving behind somebody towing trailer on a motorway at 60mph who was unsure of what they were doing when they made it???
Wasnt being nasty at all.

im not having a dig at u but no one would be doing anything if it was the case u had to have everything inspected and a ticket supplied .ive built 5 trailers and an f2 stockcar and had no training at all . self taught ive never had a weld snap yet and u dont get much more punishment than stockcar racing . all my welds are either stick or gas welding

 

[Liquid Metal]

OK mate, im not getting into an argument about some guys box trailer lol All i was getting at really is that by asking "should i fillet weld both sides for maximum strength" shows he isnt entirely confident in what he's doing, he is probably only using a single phase 180 odd amp set, therfore best thing would be to prep the joints into double sided butt configuration, rather than fillet welds for full fusion.
I didnt mention tickets, was just making point of enquiring with insurance companies as they can be really funny when it comes to homemade trailers, and you wouldnt want to find out at the wrong point that your insurance was void. Some will need it to be inspected at an MOT station or somewhere like that.
You havent had a weld snap yet........ thats all well and good, but you must understand what i mean by the defects associated with short circuit transfer Mig welding if you are a proffessional welder??

 

[dannyp]

easy way to help get a better weld with a mig is use the biggest wire you cabut it n. you can get a really pretty weld on 6mm with .6mm wire but old chewing gum may well stick better and t takes a lot of effort to get a decent weld. 0.8 is manageable. with 1.0 and 1.2 mm youd almost be struggeling to weld it badly

 

[Jan]

If I had to weld a lot of metal of that thickness I would be more inclined to go back to my old stick welder than risk the integrity of the joints with my SIP MIG. Just my 2 of course.

 

[scolliflower]

Just saw this thread picked up. I appreciate the back up and I understand the concern of Liquid Metal. The original question arose because I had never worked with that thick of material and I wanted to make sure I was thinking right and I had some hard to reach seams (the underside of upright 2 x 2 angle). I've only been welding a year, but I'm pretty into it and critical of myself. The beauty of this trailer's design (ordered from a reputable company) is that there are many weld points and only a few critical "lone" welds--one of those being the hitch, which I'm going to have checked. My machine is an Eastwood MIG 175, 220 volt, 2 phase, I believe 175 amps. I'm using .035 or .9 mm wire with Argon/C02 mix. The settings for 1/4 inch steel aren't maxed totally but close. I believe I'm getting good penetration when I watch the bead and examine the toes of the weld. But again, I've been at this a year.

 

[Liquid Metal]

Good for you...... Looking at the pictures you put on-line of the trailer and welds, looks like you doing a good job being as youve only been doing it a year or so. Also being critical of your own work...... Nothing wrong with that!!!
Only thing is you're a bit limited for power with a 175amp machine, that was why I mentioned welding fillets configure like a butt joint (as in picture below) welding in multiple passes.
Its especially good when you can only access one side because of being configured like a butt joint as in the pic below, with maximum fusion zone between weld and parent metal, and may be a fail-safe way of going about it in the future.
The method is good for when you dont have high arc power at your disposal ie spray transfer, because dip transfer mig so often looks like a good weld as your running it, especially if your moving slowly and weaving side to side (not a good habit to get into btw), and may look like a decent weld on top but the penetration is poor and sometimes non existent.

In one place i worked this was how we went about achieving a full penetraion joint between the end of a vertical 600mm square x 30mm thick column, and an 80mm+ baseplate, filling up the prep with multipass welds then building up a 30mm fillet weld between the column and plate, and a 3pass weld on the unprepped side.
Rooted with 7016 stick, then multipass filled and capped with 1.2mm wire Mig at approx 300amps in about 20passes if i remember rightly!! Plate preheated in kiln to 200deg C for 3-4 hours beforehand and end of beam preheated with oxypropane and tempilsticks to 150deg (I think, may have been 200 too lol)

In all fairness just the 30mm fillets all around the end of the column probably would have sufficed, but that was what the engineers wanted "to be on the safe side" and what the engineer wants, the engineer gets

 

[Liquid Metal]

easy way to help get a better weld with a mig is use the biggest wire you cabut it n. you can get a really pretty weld on 6mm with .6mm wire but old chewing gum may well stick better and t takes a lot of effort to get a decent weld. 0.8 is manageable. with 1.0 and 1.2 mm youd almost be struggeling to weld it badly

Providing you had the power to go with the wire size, if not its only gonna make life more difficult. With a 175 amp welder, 1.2mm wire is deffinately not going to do any better a job at all than 0.6!!

 

[dannyp]

going to have to d some prep then. 0.9 is probably the biggest wire worth running as 1mm is still probably a bit big for 175 amp