Calling Bob_VT

[chuckz]

I read this old post of your:<br />

I cut the main beam and welded the piece in using a high quality welder. I paid special attention to the alignment and made sure I ended up with a straight beam. I used lots of braces while the butt joints were welded. I did not use any gusets or extra braces.

I am looking to do something similar. I have a trailer with a 3" X 3" X 1/8" box beam tongue. The boat is a 15 foot Bowrider which weights about 1000 pound plus gear. I need to extend the tongue about 30". My plan is to butt weld another piece of 3" X 3" stock to the end of the existing tongue. I'm being told that this won't be strong enough. I crunched some numbers and can't figure out why not.<br /><br />Did your repair hold up? Would you recommend that I do the same thing or something different?

 

[craze1cars]

Re: Calling Bob_VT

My apologies for hijacking here, but I am a certified welder (however I'll admit my certification is getting VERY old so I don't have all the lastest knowledge) so may be able to help. <br /><br />Yes, a butt weld is perfectly strong enough and no braces are needed. BUT...I'd highly recommend you use nothing less than a MIG welder with the traditional CO2/Argon mix bottle...a TIG is even better if you have access to one. OxyAcetaline/Stick/arc/flux wire welders will in my opinion create too much heat at the joint and will sacrifice some of the strength, so I'd sleeve it if that's all you have to work with. And make sure you know what you're doing to get your voltage set properly for full weld penetration without burnthrough. Make sure to v-notch the joint before you weld to assure strength throughout the thickness, since you won't be able to weld from the back-side.<br /><br />If that all makes sense to you, you should be good to go. Hopefully Bob VT will also find this to confirm/deny with his experience.

 

[chuckz]

Re: Calling Bob_VT

Makes perfect sense. I'm not a welder but will have it welded by a pro.<br /><br />My other thought was to cut the two mating pieces at matching angles so It would increase the weld area and strength.

 

[craze1cars]

Re: Calling Bob_VT

Yes, a bit of an angle can't hurt, also it is common to zig-zag the joint, or at least offset it (for example longer at the top, shorter at the sides), but these both make for more complicated cuts to get a good match.<br /><br />If you're paying to have it done, I'm sure they'll MIG or TIG it. Certainly ask your welder's opinion on how to best do this, he/she's likely very qualified to tell you the best way....and may want to cut the steel to fit himself.

 

[Bob_VT]

Re: Calling Bob_VT

Yes, it held up fine. I had cut the beam and welded a piece in the middle. If you are concerned about strength you could add a brace on the underside of the beam.<br /><br />The box was the same size as yours and it did not require much V from grinding. I added in 30" of steel. We used a wirefeed with argon.<br /><br />Bob

 

[chuckz]

Re: Calling Bob_VT

I wasn't worried at all, I have just been receiving a lot of unsolicited "advice".<br /><br />Thanks for your response.