I cant say that I have ever welded much at all , and always thought that you had to disconnect your battery before welding on a car ? Is that the case or not and is it the same on a caravan , I want to get a cross bar added to my a / frame for attaching a bike holder , previously had them on the back and the bounce all round the place . So calling on any welding buffs .
Just make sure the earth lead is attached as close as possible (ideally onto the piece to be welded), also make sure the eath contact is clean shiney steel to get good contact. The same applies to welding on vehicles but disconnecting the battery negative lead gives added security
cheers
blaze
It wouldn't hurt to disconnect the battery if you are either MIG or Arc welding.
Also, ensure gas bottles are removed from the area, all combustibles, such as covers etc are removed and have an extinguisher on hand also.
The key is to ensure you have a really good earth as close to the weld site as possible. You might have to grind off some of the surface protection to attach your earth to and grind off the protection at the weld site.
Then treat all exposed metal and welds with a good coat of cold zinc once cool to prevent any rusting happening.
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John & Lynda,
The world is a book, and those who do not travel read only one page
I want to get a cross bar added to my a / frame for attaching a bike holder
Don't forget the wiring in the RHS of the A-frame. The caravan workshops remove and replace this for the duration of the process, although on one quick they flooded the frame with water for a quick weld.
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PeterD Nissan Navara D23 diesel auto, Spaceland pop-top Retired radio and electronics technician. NSW Central Coast.
Don't forget that welding will weaken the metal and A frame, far better to clamp the rack into place after all it will compromise safety and resale value. But you know this already don't you.
I have had two instances in my career as a Fitter /Welder, when welding on vehicles, Both were trucks.
Just doing a Quick Weld far away from the battery. She'll be right mate your only going to weld for 30 seconds. Clean the metal and make a GOOD Earth for the clamp.
One Battery Blew the side wall out of the battery case with a very loud POP. I was welding in the truck tipper tray.
The other truck (years later) was another quick "She'll be right mate" job. Earthing clamp on good clean metal by the weld. That battery split with a soft POP. I was laying under the Truck on the concrete, with the welding helmet on, and got soaked with battery acid.
Always, ALLWAS, disconnect them is my advice.
For 10 minutes extra effort to disconnect and reconnect the battery. Think of the$$$ for a replacement battery.
On the other hand "She'll be right mate" How many times have i heard that.
If youve not done much welding before then dont weld. Use U bolts and clamp the cross beam for such items as bike racks etc. You could do a lot of damage to the Aframe and create stress points even if the welds look OK. Plus you can remove it at a later date if you dont want it anymore without grinding it off causing even more issues.
-- Edited by Moonraker on Wednesday 3rd of January 2018 07:41:10 PM
Thxs for all the info guys , I wasn't going to weld it myself , sorry if I gave that impression , I was going to get it professionally done . I asked the question because I have twice seen a mobile welder come to the park and weld peoples vans without disconnecting the battery . Unless the owners did it before they got there . Anyway i hadn't considered u/bolts that may be a possibility . On the other hand on quite a few vans I have seen a cross member welded on an a/frame with the jockey wheel assembly attached and I assume that came from the manufacturer ?
All the above is valid advice and a qualified welder should be only too aware of these points , however one that no one has mad is make sure the tug is not connected as you my fry the engine control unit ECU and there is big $ in replacing them
Woody
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When the power of Love becomes greater than the love of power the World will see peace ! 24ft Trailblazer 5th wheeler n 05 Patrol ute and Black Series Dominator camper trailer ( for the rough stuff)
Don't forget that welding will weaken the metal and A frame, far better to clamp the rack into place after all it will compromise safety and resale value. But you know this already don't you.
Hi Kebbin
Professional welding will not weaken the metal or the A frame. The chassis and A frame is constructed by welding the individual metal pieces together at the factory.
The problem is with the "experts" who think they know how to lay down some metal with an arc. Sometimes that's all they do
Don't forget that welding will weaken the metal and A frame, far better to clamp the rack into place after all it will compromise safety and resale value. But you know this already don't you.
Hi Kebbin
Professional welding will not weaken the metal or the A frame. The chassis and A frame is constructed by welding the individual metal pieces together at the factory.
The problem is with the "experts" who think they know how to lay down some metal with an arc. Sometimes that's all they do
Jaahn
Jaahn, you were obviously reading someone else's post as I didn't mention Professional Welders nor did the OP, having worked with Boilermakers however I would trust some of them as they usually have far more knowledge than the average welder professional or ticketed.
TAJ is correct. It is bad practice to weld across the grain on RHS (90deg to its length or acrodd the beam) if that RHS beam section is being used to take loading such as on an A frame.
Any repair to an existing crack in this situation would most likely involve welding steel plates to repair ensuring again that any welds are not placed across the grain thats if its not practical to cut out the cracked section and welding in new.
The manufacturing process of RHS and other tubular sections of steel create a product that is highly stressed good boilermakers and product design engineers will ensure fabrications made from these types of steel section are welded together taking this into consideration.
Don't forget that welding will weaken the metal and A frame, far better to clamp the rack into place after all it will compromise safety and resale value. But you know this already don't you.
Hi Kebbin
Professional welding will not weaken the metal or the A frame. The chassis and A frame is constructed by welding the individual metal pieces together at the factory.
The problem is with the "experts" who think they know how to lay down some metal with an arc. Sometimes that's all they do
Jaahn
Jaahn, you were obviously reading someone else's post as I didn't mention Professional Welders nor did the OP, having worked with Boilermakers however I would trust some of them as they usually have far more knowledge than the average welder professional or ticketed.
Having worked with & supervising 100's of boiler makers, & Certified "A" grade welders ,in the heavy steel fabrication industry [including pressure vessels for power houses, oil refineries , components for the pumps & turbines for SMEC [Tumit] & Wivenhoe ] ,would not leave most of of them anywhere near critical welding
-- Edited by oldtrack123 on Friday 5th of January 2018 12:07:53 AM
I suppose oldtrack is referring about me as one of his hundreds of boilermkers
which he knows nothing about me or my quilifications going to join macca seems when specialists in there field answer they always get knocked down
I was referring to no one in particular on this forum, but if the cap fits
I have had many top class boilermakers working under me[ That was the type of work we did] & none of them were top grade welders or knew much about top grade welding,nor did they want to.
Referring to your post ; I see nothing wrong with it .nor have I made any comment on it. but perhaps you could have added a little more detail
Like :
Making sure the earth /return clamp is as close to the weld as possible ,with NO bolted or similar joints between it & the weld area
That is the most important point with any thing that has electrical wiring .Simply because of the damage that can be done to the wiring due to it shunting some of the welding current& overheating /burning the cables out
In extremely critical cases where the parts ares not electrically continuous , connect an earth /return clamp each side of the weld area
The term earth should not really be used,as any connection of the welding circuit to "earth " should be avoided, but not always possible.
A requirement under the Standards for many years now
-- Edited by oldtrack123 on Friday 5th of January 2018 03:59:54 PM
Polarity AC or DC type welders come into it .. But often the clamp type can be a little taken for granted . A bolt through lug as close to welding as said . Grinding off any paint etc .,
