Thank you for your detailed explanations with examples sir 👍 I've always believed in replacing like for like. To cut out any corroded metal and replace with fresh metal of the same thickness, I do use galvanised steel for repairs when I can. This would normally be thinner parts like bulkhead repairs, but I think the galvanised steel gives a little protection to the weld from corrosion. However respiratory protection from the poisonous gases are more hazardous than normal welds so good ventilation and respiratory face mask are essential. I also find my cheap plasma cutter is great for cutting out the rotten steel to good steel. Much easier than using a cutting wheel in awkward spaces too.

These videos are awesome! Please keep them coming!

Hello from Canada. Love your channel. My 1976 101 was happy to hear about your vehicles and adventures. We both look forward to more videos, especially as I recently declared myself retired, and hope to spend more time with it and my FJ55, and the rest of the family of course.

Thank you Bill, dispelling myths and legends.

Very educational I learnt a lot

Hi Bill. You mentioned other people using heavy plate. You are correct. I would have also said that the use of heavy plate moves all the forces somewhere else which can show up as failure. In other words, chasing your tail. Good video. Thanks :-)

Very informative as per. I lost a good truck to chassis corrosion. The welds are the early starting points, so glad you pointed out the problem with slapping on and welding a plate. Pete

Excellent video Bill. You really are a proper engineer - it's such a misused title which is often totally misrepresented in the UK. Looking forward to the next installment.

Very useful information, really enjoying your videos Bill!

The rust proofing needs to start when the vehicle is new, gallons of expensive snake oil on top of mud and rust inside the rails just makes repairs more difficult,

Bill, I quit on this long ago. Now, I simply “Fluid Film” the entire vehicle including the chassis inside and out, the under body, inside panels and anywhere else rust may occur. It is greasy, but it is simple and easy. Just spray it once a year and forget about it.

Excellent work as always, Bill. My concern for older vehicles are these: We often see rusty chassis, cleaned up, and repainted. People may not know how much material thickness is retained or the condition inside the chassis members. Are there cracks? With 2mm wall thicknes, could we be down to 1.5mm? Perhaps 1mm or even less. A hole is zero retained thickness. Older vehicles are often modified to accept heavy items such as winches, bumpers, anchor points. Are standard chassis members sufficiently strong for such modifications and the uses? You will cringe Bill, but I made cardboard patterns of my chassis and have had plates made to reinforce my entire chassis, then pool welded and butt welded these to my chassis (after spray galvanising). The plates are 3mm in the lower flange and 2mm in the webs of rails and cross members. All through-bolting points are reinforced on the opposite side to ensure the members are not crushed. I have reinforced the brackets where the front control (leading) arms are bolted. I have used the same steel grade as LR claim to have used. I am not an expedition user so loss of payload is not critical, but my vehicle does get used in extremis.

Later LRs rust from the inside out! To save cost, chassis were made with triple skins in high stress areas, where extra strength was required. This means that water gets between the skins, and weakens the most critical areas of the chassis. Essentially, when the corrosion makes it to the outside world, the chassis will have been weakened so much it's ready to break in half. The calculations outlined here, certainly apply to a brand-new chassis, but one which has seen any amount of use somewhere as wet as the UK, will be affected by corrosion to some extent. Old series LR chassis, were made out of far more substantial material, and last much longer than the later multi skin designs.

I’m only a carpenter so take this with a handful of salt. My experience is with my 110 LR chassis repairs and modifications. I have cut off all the suspension mounts and removed the A frame cross member. (To reinstall in different locations to change the links in length and geometry) Regarding crevice corrosion, the sections that were fully seal welded have little to no rust between the two surfaces, with bright untreated steel still showing not much different from when it was installed. The areas only partly welded were terrible traps and introduced corrosion in unseen and in unpreventable areas. Behind the A frame cross member was bad where it attaches to the main chassis rails. Even behind the removable transmission cross member was bad. In the area behind the gearbox cross member, I’m not happy with just treating the rust and leaving it, I have also decided not to cut it out as there are formed angles (3-4mm thick, say 30-40mm wide) inside the corners of the chassis and these are spot welded to the to C section halves before the full longitudinal welding down the centreline. I’ve chosen to overlap the web with a doubler, but formed in a C section to avoid welding to the radius corners where stresses are trapped. Regarding the cutting of chassis’s, repair sections etc on angles, it’s my understanding that this reduces stress risers as it changes the direction from being generally perpendicular to the load forces. Commonly cut at 45 degrees. It’s definitely bad practice to weld straight across a flange (I avoid it on webs also) For those that have access to instagram, my account is Kustom110

Great video mate

Very interesting 👍

Slightly off beat question here, but if building a chassis mounted spare wheel holder that might see some service in arctic climates, what grade of steel would you suggest ? I seem to be arriving at EN24T but also see stainless steel grades cropping up as very suitable for duty down to -45 deg C. (316 L apparently being better for welding if over 6mm thick). Any ideas welcomed ! Rgds, Phil