Welding

[David28]

Hi I'm wondering if anyone can help I need to do some welding on my lexus rx400h 2008 model and I'm wondering if to power down and isolate the hybrid Battery, is it as simple as removing the isolation fuse plug or are there any other steps that need to be followed 

[Malc]

16 hours ago, David28 said:

I need to do some welding on my lexus rx400h 2008

Wot on earth could need this doing on such a newish car for heavens sake  ???

Malc

[Herbie]

17 hours ago, David28 said:

Hi I'm wondering if anyone can help I need to do some welding on my lexus rx400h 2008 model and I'm wondering if to power down and isolate the hybrid battery, is it as simple as removing the isolation fuse plug or are there any other steps that need to be followed 

Somewhere around here there's a PDF file documenting how to work safely around the hybrid Battery and its components and I'm almost sure that taking out the Service Plug Grip is all you need to do as this isolates the HV Battery.

HOWEVER - I can't be held responsible if this advice is wrong and you must confirm it 100% yourself before relying on it 

[Barry14UK]

Is it also advisable to disconnect the 12v Battery prior to welding have you established?

[Mihanicos]

Disconnect the 12v Battery and remove the Battery ground from the body and the gearbox. It is also advisable to disconnect all ground points of the car.

When welding, keep the ground as close as possible to the point you are welding. Make sure you clean the ground point to a clean bare metal, this will ensure that the current will flow to the welding point directly. Remember the current always flows through the lowest Ohm resistance, hence the need for a zero ground resistance in the welding circuit, otherwise the current will flow through the car's ground wiring, causing catastrophic damage. A good practise is to remove the safety plug too.

Chris.

[Keeling54]

My 2006 Rx has just failed the MOT on a crusty rear end and needs some welding done. Quite a few place steer clear of welding hybrids but my local guys are willing to give it a go. I've told them to disconnect the 12V aux Battery, pull the HV plug and get on with it. 

I'll report back when they've finished.  

[Keeling54]

Thought I'd update my previous post. 

The MOT was re booked for the welding to be done, the tyres, drop links and binding brakes had been sorted. 

Got a phone call 10 minutes after I dropped it off, only to go back and find this. This isn't actually what it failed on. I have a welder coming to take a look and a body shop putting a price to it. Wish me luck. 

 

[Russell Wheeler]

It is hidden under the cover sills, so weld plates on, then put the cover sill back on. You won't see it. Is the otherside similar ? - Might be worth rust proofing it (unless it's already too late)

[Russell Wheeler]

On 1/19/2022 at 1:30 PM, Malc said:

Wot on earth could need this doing on such a newish car for heavens sake  ???

Malc

15 years old, the underside of these cars does not seem very well rustproofed. I have been out with a wire brush, hammerite and waxyoil with mine - and it was quite rusty - commented on the MOT

[Keeling54]

2 hours ago, Russell Wheeler said:

15 years old, the underside of these cars does not seem very well rustproofed. I have been out with a wire brush, hammerite and waxyoil with mine - and it was quite rusty - commented on the MOT

The underside of mine is fine at the front but unbelievably rotten at the rear. If I keep it going I can see it needing a new rear subframe at some point soon. 

[Keeling54]

2 hours ago, Russell Wheeler said:

It is hidden under the cover sills, so weld plates on, then put the cover sill back on. You won't see it. Is the otherside similar ? - Might be worth rust proofing it (unless it's already too late)

There is a small section under the rotten bit just next to the jacking point that caused it to fail the MOT, when I get that fixed I'll get the hole plated over and put the sill cover back on. I'll also Waxoil the void both sides.

According to the body work guy and I tend to agree with him, the rear corner was badly repaired at some point and has rotted from the inside out. The other side is fine. 

[Restorer]

15 hours ago, Keeling54 said:

The underside of mine is fine at the front but unbelievably rotten at the rear. If I keep it going I can see it needing a new rear subframe at some point soon. 

Had a new rear subframe on my RX300 (53 plate) earlier this year at MOT time.

Got a second hand one from a company that imports breakers from Japan (no salt). Still cost me around total fitted £1500 all told.

[Malc1]

7 hours ago, Restorer said:

Had a new rear subframe on my RX300 (53 plate) earlier this year at MOT time.

Got a second hand one from a company that imports breakers from Japan (no salt). Still cost me around total fitted £1500 all told.

But worth every penny for the car you know and want to continue with …… what people pay for new cars with depreciation and finance costs makes keeping these ‘ loved ones ‘ a sensible choice 

Malc 

[Greisingel]

Yikes! I am crawling under my 2005 400H with cleaner, de greaser, and hammerite.

That is quite scary. Do you live by the sea?

[Keeling54]

On 11/13/2023 at 4:35 PM, Greisingel said:

Yikes! I am crawling under my 2005 400H with cleaner, de greaser, and hammerite.

That is quite scary. Do you live by the sea?

No, miles from it, previous owners were no where near the coast either. 

[Keeling54]

Still not had the welding done, the mobile welder guy has let me down, 2 body shops not interested due to the amount of fabrication works needed. I did tell them they could plate over both but they weren't interested. 

I'm now looking for a body cut so I don't need to fabricate from scratch, I'll then buy a welder and give it a go myself. 

[Greisingel]

You could try going through a forum. I taught myself basic MIG welding (you can pick up a welding machine for less than £300) in a bid to save my old BMW E39 540i, which as it turned out was too far gone rust-wise. We're going back 8 years now (how I miss my V8...rust bucket)

But the guys'n'gals on this site were very helpful and one offered to help if I got the car to him. Cash in hand etc etc. And he had photographs of the work he was doing on an old VW camper whose metal frame work was rust swiss cheese ie he was talented.

https://www.mig-welding.co.uk/forum/

[Barry14UK]

I have a budget MIG welder which I have used for a few jobs and results OK if not pretty.  I know I could do a better job with a better model and gas.  You could fabricate all the steelwork yourself and fix in place with self tapping screws which is a method I have used, particularly where welding clamps can't be used.  The self tappers can be removed later and and the holes filled with weld.  You could hire a decent quality MIG welder and either do the job yourself or have a professional do that part of the job, which will save paying  equipment hire as a Pro will have good equipment and welds will be better than a novice will achieve.  When I did my last repair which was spot welding, I used 'weld through primer' so it could be worth asking a proposed welder if he wishes this applied before the plating is fixed in position.

[Keeling54]

I managed to find a mobile welder, he's fabricating the plate and sill repair section tomorrow. I'll post up some progress photo's when he's done. 

Buying a welder and doing it myself was my last option, fortunately I found a man who can. 

[Greisingel]

On 12/8/2023 at 8:38 PM, Keeling54 said:

I managed to find a mobile welder, he's fabricating the plate and sill repair section tomorrow. I'll post up some progress photo's when he's done. 

Buying a welder and doing it myself was my last option, fortunately I found a man who can. 

Yes its the form work that needs a professional touch. I can drop spots easily enough. But cutting and shaping the plates...hmm took me back to my school metal work days and the D – I usually got.

[Keeling54]

Just to update this one, the man that I found that could weld sorted it for me, not the best job I've ever seen, but after I covered it in bilt hammer hydrate 80, a coat of paint then some tetroseal, it got another years ticket. 

This is the only photo I have, he was just in the process of seam welding the top section and adding some more welds to the lower jacking point.  

With the cover back on no one will ever see it. 

[Malc1]

Well done ….. lives another day or even a year 👍

Malc