Welding question

[Muggnz]

hi,

Is this suitable for welding to the underneath of the tongue centre rail? And are the 2 pieces matched enough, to be welded to each other? Or do they need more grinding?



tia
david

[mb82]

I would take the paint off and maybe take a little more out of the back to get the front to match a little closer. It won't take much so one pass with the grinder on each side and check it each time.

[Dale M.]

The better the match the easier the weld , the stronger the weld...

Dale

[brian_bp]

I don't weld, but I did fit a roll cage together for my race car and had it welded. My welder would have refused to weld a joint with that gap, but then he was doing precision TIG work, and was picky, which is why I picked him.

I would try for a better fit, especially since the flat mating surfaces are easy to do.

I don't see any problem with having a weld along the bottom... and in this case it would be hard to avoid.

But what are these pieces... reinforcements? Or is the tongue in the background just for angle comparison?

[Muggnz]

This is what the tongue looks like. The 2 pieces are intended to bring the tongue up to the required strength. So that it won't break when my TD drop gets completed. The existing diagonal rails aren't strong enough.



And after removing rusty cross members.


I think that the 2 diagonal tongue rails are going to have to go. To reduce weight & to provide patches for the holes in the center rail where it met the cross member. The 2 rails shown & a new cross member cost $140 , so I'll need to recycle the old rails.

I'm leaving the paint on until just before welding starts.

[Muggnz]

PS. The grinding shown, took me an hour or so including the measuring.

I use a 100mm ( 4" ) Black & Decker. Not the most powerful, but it gets there. And makes it harder for me to take to much metal off.

I've just had a thought. If I clamp them side by side. Then it'll be easier to get the faces identical. Or at least a closer match.

[Leon]

If it is a TIG I would fit the pieces together better, but with a MIG a little gap will give better penetration since you will have to linger longer in the weld to fill the gap.

[Chicken Legs]

Im kind of confused as to what you are trying to accomplish. Reinforce the tongue? If so it doesnt look bad, my suggestion would be to add some gussets under the tongue where the three pieces meet, and possibly gussets at where the tongue meets the box framing. The brace that you cut out should be replaced possibly using a larger piece of tubing that you can slot to fit around the existing tubing. As for grinding, you can buy those 4" grinders, and you can also use 80 grinding disk on them for some fast results on thin metal. Its great for cleaning up welds both before and after welding. Good luck.

[Muggnz]

Chicken Legs,

I am trying/going to strengthen the tongue. So that it exceeds Andrew's Tongue Strength Calculations page. So that I don't have to replace or fix it after the TD is built.

The 2 new blue rails will fit under the frame, like Gerdo's. And meet under the centre of the centre rail. The 2 angled rails will then be removed, cut and used as supporting plates for where the front cross member met the centre rail.

thanks, I hadn't realised that sanding disks come in different grades. It should've been obvious.

david

[bobhenry]

hi,

Is this suitable for welding to the underneath of the tongue centre rail? And are the 2 pieces matched enough, to be welded to each other? Or do they need more grinding?



tia
david

Took a trade school welding class held at Purdue University. Our instructer was a retired Conoco storage tank production welder. His favorite quote was a good welder can weld anything he could step across.
I quess if you are welding the spiral stairs to the outside of those huge tanks one step at a time you have a real incentive to get real good real quick.

Looks like you got a Hell of a rebuild .Just remember it's easier to get it right now than when you have it 90% complete and realize you have a frame problem. Lots of Luck

Bob

[Muggnz]

thanks Bob.

I agree.

[Chicken Legs]

My thoughts are that if you weld those tubings under the tongue for a patch job, it will always look like that,,,,, a patch job. My recommendation would be to cut out the tongue and replace it with new steel. Granted it may be more work but I wouldnt want to build a nice trailer only to have to explain the patch job from now on.

[Muggnz]

Chicken Legs

I'm not to worried about the looks. More about being able to use it long term.

I'm planning on a tongue box to hide some of the patches.

david

[Muggnz]

progress report & another question.

I've done some more grinding and achieved a better fit.




And at the same time done a trial fit.


Is there any recommended minimum distance for the blue beams to be behind the front cross member? Before they are attached to the 2 outside rails? In order to gain a vertical tongue strength that'll be up to the job.

[angib]

Is there any recommended minimum distance for the blue beams to be behind the front cross member?

200mm (8") would be enough, if it's tight.

I do think it would be better to fit them after the front cross-member is in place - the tongue pieces need to be a close fit to the cross-member.

Andrew