Welding Tips and Tricks

Just bought a boat. Boats great. Trailer not so much. Is this weldable? Or should i just get a new trailer?

Hey,

Welcome to the forum.

The question is not "is it weldable" because yes it is, but need fixing first, but "how can i design this repair so it doesnt happen again" It looks like accident damage has really caused a whoomph in the rhs, and the whole piece needs replacing,

Mick

To me it looks like the angle to which the winch post is welded is too short allowing amplification of forward and back load on the rhs runner causing a fatigue fracture and maybe from front end impact as well. The winch post gusset (very flimsey) also shows signs of these forces.
I would replace that section of rhs runner and also increase the length of the winch post bottom angle by another 4" forward minimum and fit proper gussets to the winch post. This should prevent this fracture from returning.
Show us the fish!

Weld the crack up with 3/32 7018, grind it smooth, fish plate it with 1/4 inch flat bar.
Weld it all up, paint it.

Done!!

Hey,

Not meaning to critisise John, but there is more going on here than just the crack, and likely the whole member is damaged beyond repair. It looks like the upright is adjustable (for a different sized boat??) so a fish plate is out of the question. If ya really good, you could cut out the damaged section and weld in a new length and put the afore mentioned plates on the inside, the same way Jody did in his engine hoist video.

Mick

OK - so from other boat trailers I repaired I'd say this is a combination of things - the piece that bent is smaller than the rest of the drawbar as it's slid inside the main part - usually to make the length adjustable to a degree to suit boat shape & towing vehicle - this creates a weak point which is where the fold is - likely cased by too much tongue weight & rough roads - this is usually aggravated by people winching the boats bow eye right up against the winch - all trailers flex - boat trailers especially - but with the boat being fairly rigid once the bow is held to the winch it attempts to hold the trailer from flexing up to that point - the last few feet of drawbar now takes all the flex & shock load from the road - so to fix this I would say - allow a gap between the loaded boat & winch - maybe place an old tire or something in between so the two can move around freely - obviously strap the boat down - but allow the trailer some give - I would do away with the sliding part - measure how long you require & obtain a new section of RHS the size of the main piece - cut off a short undamaged section of the bent original - weld this into the drawbar first - now slide the new piece over leaving a slight gap so you have a root gap right round the joint to weld - if you want to be really sure add a doubling plate to the outside 2 sides after - make this a diamond shape with rounded ends not square so there is no straight line stress point on the new piece.

I'm with Mike on this one.

OK - I commented assuming I was doing the repair & I'm confident having done plenty of this kind of job before - but not knowing the skill level of the OP &equipment available to him maybe safety should come first ! - trouble is I'm from a farming background so I'm always going to get by somehow - buying a new trailer never occured to me !

One of my oldest pearls of wisdom is "all farmers are gamblers, some take a lot of pride in risk taking and getting away with it." If electrical conduit is the most cost effective way to do it, lets use black plastic water pipe. Many are willing to pay extra to have it fussed up!

Infernalmc,
to help us zoom in on this one, can you remove the winch post and post another pic because something wierd is in play here. The bottom of the rhs runner looks in line but the top looks like it steps down at the weld. Maybe some dodgy joint will be revealed once the winch post is out of the way.

Can you get us a bigger picture??

I'd like see all the variables.

Thanks,
John

Just because you can see all the variables doesn't mean that you can solve the formula my friend.

As Mick stated, why just repair when you can prevent it again? Yes, you can stick weld it, grind it smooth and fish plate it, but will that fix the original problem? Yes, it will. Will it prevent it from happening again? Maybe, but to me it looks like it took a sharp, heavy impact, on top and from right to left (i.e. towards the rear of the motorcycle in the background) just based on the way that metal looks like it is swelled out on the sides. I doubt it was a sustained load, or else the entire piece would be deformed around that area. Coldman could be on to something as well, with a dodgy joint or something, but as he stated earlier in the same post, the bottom looks too straight for it to be a separate piece.

I'm not going to sit here and lie to you all and say that I've built a boat trailer, or repaired one for that matter, so I'm kind of at a loss as to what I'm looking at with the winch post or whatever it is. My whole thing with John's solution is this. If you just fishplate everything that cracks without ever doing any research, you're not really accomplishing much other than laying down practice beads on someone elses dollar. Not at all saying that it won't work, because obviously it can and will work in most cases. And apparently you doit and make money doing it when you're not on here saying welcome to the forum.

I'd like to see a bigger picture of the trailer.
Let's see the corners, stress points and all.
I made a recommendation based on what I saw.
If something needs reengineered, then patching it up won't help.
Just gave my $00.2,
John

Btw Sam,
Welcome to the forum.
Yes I've said many things that don't make sense, but don't judge me by it.

Looks like a tongue replacement is in order. Not sure why that weld is there anyway...maybe a stop for the bow catch post? Looks like it has been moved from the original location, maybe for to accommodate a shorter boat. Is the tongue welded to the frame members or bolted? If bolted, just buy new tongue material and put it together. If welded, you will still probably be money ahead to grind it free and replace it (added peace of mind anyway). How heavy is the boat?

"Dodgy" is a good description. The step-down in the weld in front of the winch mount suggests someone has "sleeved" smaller tubing into the frame as a quick fix. So much for the quick fix.

I am a bit surprised the break is on the top, rather than the bottom, but perhaps the corrosion is the give-away.

I'd pull the winch mount off, cut the junk out several inches behind the winch mount, and weld a new tongue in the correct dimensions to it, with an inner sleeve salvaged from the undersize tubing to serve as weld backing.

This is based only on what I see in the photos. Were it in front of me, I don't promise this is the course I'd take.

Steve S

I know I just posted about my poor eyesight but I don't see a weld at all in these pictures. It looks to me as if they pulled too much weight with the winch and compressed the tubing, bulging out the sides. Then after the fact, they removed it and put it back on behind the damaged area. I'm guessing that this caused a stress riser here and then when traveling up and down the highway flexing caused it to crack where it did.

As to a repair, I'd replace the whole tongue with a new piece of heavier tubing and be done with it.

Len

Good catch Braehill, zooming in it shows up much better. The rusted area shows where the winch had been mounted. It looks like the top of the tongue was crushed by the rear of the winch plate as the post was being torqued to the rear. Too much bow weight maybe.

I'd still replace the tongue...

Literally, pointed this out to Braehill on the phone yesterday... what does he do? Gives me no credit, and pretends it was his idea!!! You old people (dad) have no respect any more!

Alright, I'll relent, he did have a small input when I talked to him on the phone, but mostly he just added to what I already knew. This is a case where two heads might not be better than one, when one is just looking for credit. That's the best I can do, I don't want your head to swell.

Len

Maybe someone jack knifed the trailer backing it up. If you can replace the whole tongue I would just go that route and bump it up a size.

The returning issue of future cracking is minimal IMO, considering the age of that trailer and how long it took to get to that point. The damage is from abuse, maybe to much tongue weight. Someone, maybe you, moved the winch stand back after the damage was done. I would cut it off and sleeve it inside, weld it, grind it flush, then paint it.
You did say "should I just buy a new trailer". This leads me to believe you can afford not to fool with it? It's up to you.
Ya, it's my first post, but fixin boats and their trailers is what I do every day.
Best of luck, Kent