Bending Trailer

[Bigmuz7]

Originally Posted by jwalker

Oh ye of little faith.

But how brittle will it be ? Looks good enough, but wont bits of zinc be entrapped in the weld, usually by way of a gaseous state as the arc or gas melts it ?

[jwalker]

Originally Posted by Bigmuz7

But how brittle will it be ? Looks good enough, but wont bits of zinc be entrapped in the weld, usually by way of a gaseous state as the arc or gas melts it ?

Nah, the zinc's melting point is so low that some of it evapourates and the rest blows off as oxide. I dare say that if the weld metal was analized it would contain traces of zinc alloyed into the steel but why would that be a problem? Why do you think it might become brittle?
I'm also not suggesting that the weld is done by simply welding directly onto an unprepared joint. The metal edges do need preparation and removal the the zinc each side for a short distance.

I'm not recommending the use of stainless welding of mild steel in general but it's a way of welding galvanised steel and imparting a worthwhile degree of rust resistance to the weld area. Although, I have used it for welding mild steel where I felt rusting would be a problem and its been remarkable how resistant to rusting the adjacent metal has become.

As usual, it's what I've found to be successful.

[Bigmuz7]

Originally Posted by jwalker

Nah, the zinc's melting point is so low that some of it evapourates and the rest blows off as oxide.

Some of it does , but some of it gets in the weld and forms an alloy which is weaker than the weld

Originally Posted by jwalker

I dare say that if the weld metal was analized it would contain traces of zinc alloyed into the steel but why would that be a problem? Why do you think it might become brittle?

Because the zinc and the process of oxidisation end up being in a gaseous state within the weld.

Originally Posted by jwalker

I'm also not suggesting that the weld is done by simply welding directly onto an unprepared joint. The metal edges do need preparation and removal the the zinc each side for a short distance.

Yep I can see that, but a lot of peeps forget to remove the zinc from inside the joint of either piece, which is very hard to do, especially in square section, and it doesnt take a lot of contamination to weaken the joint

Originally Posted by jwalker

and imparting a worthwhile degree of rust resistance to the weld area. Although, I have used it for welding mild steel where I felt rusting would be a problem and its been remarkable how resistant to rusting the adjacent metal has become.

I've found the rust resistence to be very variable, and tbh never found out accurately why, I suppose the metal content of the welding anode has a lot to play here, as I dont know what make up of fluxes are used (in Sticks... MIG's just get thrown off Galvy stuff), this is even after properly treating the welds for protection after the weld

[jwalker]

Originally Posted by Bigmuz7

.... MIG's just get thrown off Galvy stuff), this is even after properly treating the welds for protection after the weld

We must weld differently then cos that's mig welding. I haven't used stick welding for years. MIG or TIG for me. I was going to suggest you go and try it before judging it but if you can't even make a MIG weld on galvanised stuff then there would be no point.

And it isn't full of bubbles as I think you are suggesting...I know, cos Angle Grinder is me middle name.


PS. analysed. It's strange what one doesn't notice after a bottle of Newcy Brown before ya evening meal. Hic.

[Bigmuz7]

Originally Posted by Bigmuz7

MIG's just get thrown off Galvy stuff

I meant that this as a consequence if you dont remove all the zinc

[Jono]

Originally Posted by jwalker

Nah, the zinc's melting point is so low that some of it evapourates and the rest blows off as oxide. I dare say that if the weld metal was analized it would contain traces of zinc alloyed into the steel but why would that be a problem? Why do you think it might become brittle?
I'm also not suggesting that the weld is done by simply welding directly onto an unprepared joint. The metal edges do need preparation and removal the the zinc each side for a short distance.

I'm not recommending the use of stainless welding of mild steel in general but it's a way of welding galvanised steel and imparting a worthwhile degree of rust resistance to the weld area. Although, I have used it for welding mild steel where I felt rusting would be a problem and its been remarkable how resistant to rusting the adjacent metal has become.

As usual, it's what I've found to be successful.

JW, I think we're going to have to agree to differ on this

[jwalker]

Originally Posted by Jono

JW, I think we're going to have to agree to differ on this

Fine; but first, go and get a couple of bits of 6mm galvanised steel, bevel their edges for about half the thickness, take back the zinc for about 2-3mm along the edges, lay in a stainless weld, grind a bit of it to check whether it's porous (If you can weld, it won't be.), test it with the sledge hammer and then come back and apologise.

[Jono]

Originally Posted by jwalker

Fine; but first, go and get a couple of bits of 6mm galvanised steel, bevel their edges for about half the thickness, take back the zinc for about 2-3mm along the edges, lay in a stainless weld, grind a bit of it to check whether it's porous (If you can weld, it won't be.), test it with the sledge hammer and then come back and apologise.

Jeff, since my livelihood and that of the forty odd people I employ depends on me knowing a thing or two about stainless steel welding and fabricating ……of which we produce hundreds of tons a year all of it in very severe service conditions… I think you’d agree that I do a little more research into things than hitting it with a hammer to see if it breaks.
I agreed to differ rather than bore everyone else to tears with the technical explanation of traces of zinc and the effects on the granular structure of the weldment…that’s for two reasons…the first is as a humble Fabricator, I take guidance from the more technically qualified, especially when they back it up with evidence…….and secondly they lose me as soon as they start using words of more than two syllables…
If you really must argue, I suggest you look at some of the excellent papers written by the Engineers at The Chiyoda Company of Japan, or Mitsubishi Heavy Industries. Companies that have a great deal riding on the integrity of their equipment. Their work on all forms of cracking in S/Steel in service is most informative

…..as to your experience in this matter….don’t confuse being lucky with being right.

I don’t think I’ll be apologising anytime soon….

[Chris]

Gold old Ribnet. 11 pages on how to repair a trailer and no one has yet suggested bracing it with pieces of wood lashed on with tie wraps. I'm certain it would work

[jwalker]

Originally Posted by Jono

….don’t confuse being lucky with being right.

That's a good one. I'll keep it in mind. It's lucky I've been lucky often.

I don’t think I’ll be apologising anytime soon….

I didn't expect you would be.

I agreed to differ rather than bore everyone else to tears with the technical explanation of traces of zinc and the effects on the granular structure of the weldment…

I wouldn't be bored with that. Better than reading again how to clean tubes or how to enter an MMSI.

Argue, I thought this was a discussion.

[bedajim]

Originally Posted by Chris

Gold old Ribnet. 11 pages on how to repair a trailer and no one has yet suggested bracing it with pieces of wood lashed on with tie wraps. I'm certain it would work

Stainless jubilee clips and a piece of box section permanent repair

[Hightower]

Naa, don't use anything, just use it till the drawbar drops off

[Bigmuz7]

[Jono]

Originally Posted by jwalker

That's a good one. I'll keep it in mind. It's lucky I've been lucky often.

........

They do say "The Devil looks after his own", don't they..?

[Hightower]

The long awaited bracing fabrication has been made. I have offered this up to the draw bar area that has the bending problem. As the draw bar was no longer at the correct angle I thought that by doing the U bolts up would help straighten the thing up, I was right to a certain extent but as you can see from the photo's there is some way to go and can't get any more clamping effect from the U bolts (thread stripping ).

I'll have another go tomorrow but might opt to driving the RIB and trailer around tomorrow, getting a full tank will help in the hope of the drawbar settling out a little.

Meen while if there are any suggestion as to how to straighten out the draw bar I'd be interested to hear how.

[Limey Linda]

I would be very concerned about that approach. To try and get it to conform to the new support could induce a huge amount of stress into the whole thing. I would slacken is off a bit and put in some steel wedges to close the gap and re-tighten. You do not want to hit a pothole in the road and something breaks loose with a bang.

[Hightower]

You think it would?

I'd have though that with the extra strength the fabrication offers, that the whole area will be more ridgid once tight and hence less likely to bend or break.

[Endeavour]

I don't know whether its of any interest but I think it was Peter Connors who owned Admiral, I was told that he was (a while ago) something to do with Indespension. Thats why some of Admiral Trailers looked very similar to theirs. The reason am saying this is that maybe an indespension drawbar will fit as a direct replacement for the existing one.......

[Hightower]

Originally Posted by Endeavour

I don't know whether its of any interest but I think it was Peter Connors who owned Admiral, I was told that he was (a while ago) something to do with Indespension. Thats why some of Admiral Trailers looked very similar to theirs. The reason am saying this is that maybe an indespension drawbar will fit as a direct replacement for the existing one.......

Thanks Steve, the indespension trailers are different. However, looking around in some boat yards lately has shown the same design used on snipe trailers so this might be a solution if this Idea doesn't work. I've also got a name of a fabrication company that makes trailer bits if all else fails. Trouble is, it's taken so long for this piece to be made I'm missing out on some nice weekends of boating.

[Limey Linda]

Originally Posted by Hightower

You think it would?

I'd have though that with the extra strength the fabrication offers, that the whole area will be more ridgid once tight and hence less likely to bend or break.

I am just saying it could. There is nothing wrong with the fabrication, just the attachment. What grade U bolts are you using? I they are Chinky cheese they could pop. If you wedge/pack the gaps it will be just as strong and no risk of something going bang. Yes, I have had a trailer bar go bang on me and I was 15 miles from a paved road. Thank god for baling wire. Your alternative would be to heat up the bent bit whilst tightening the U bolts.