Rebuilding the chassis is the most adventurous task I’ve ever attempted on a car so there was more than a little trepidation as I cut into the first rotten outrigger. Before I began I got hold of detailed drawings of the chassis courtesy of Triumph guru Bill of Rarebits4Classics. These drawings are absolutely critical to anyone rebuilding a chassis as any misalignment will result in problems with steering or body alignment. In fact one of the first Heralds I ever owned did not sit level and it transpired that a rear outrigger had been fitted badly leading to a lilt to one side, that particular car needed a lump of concrete in one side of the boot to get it through the MOT – but those ‘fixes’ were par for the course in the ‘70s.
I digress. I then cut a piece of 2” angle iron to the same length as a side rail, and using the new rail as a template drilled 9mm holes in the angle iron to match the outer two body mounting fixings. This was then bolted tightly to the rotten outriggers and a G-clamp used to hold the central outrigger to the angle iron. Now by replacing one outrigger at a time I could ensure they all remained level and that the body mounting holes would be in exactly the right place.
This now left me with the problem of ensuring the outriggers attached to the main chassis rails in exactly the right place. The drawings were my first reference point but I also took my own measurements from fixed points on the chassis. Safe in the knowledge I now knew exactly where the outriggers needed to be located I set about removing the first rotten one with a hacksaw. Once removed I used an angle grinder to remove the remaining scrap metal ensuring I had a clean and perfectly level surface to work from.
Unfortunately when completing a couple of the outriggers I did find small bad areas on the main chassis rails but I was now able to cut out the bad metal and weld in plates to make good the chassis. Thankfully this rot wasn’t bad by any means, otherwise I would have needed to source another chassis. Once a plate was in place I could temporarily clamp on a new outrigger using a large G-clamp. Following some very careful measurements I began welding the new outrigger in place, starting with just a couple of tack welds until I was satisfied with the positioning. This was followed by welding everywhere the outrigger contacted the chassis, including the inner edges to be absolutely certain these weren’t going to fall off.
I then repeated the same process for the remaining four outriggers. My welding skills leave a lot to be desired but I am satisfied these outriggers are going nowhere soon! Once all outriggers were welded in place I was able to fit the side rails. After checking the measurements against the detailed drawings I was able to weld the new side rails in place.
The next task is to remove all the underseal and sticky oil from the main chassis rails. This is a horrible job as it’s extremely messy and there’s no quick way I know of. I used a blowtorch to soften the underseal (risky process, better to use a hot air gun) and ordinary paint scraper to start removing it, It soon became obvious that the underseal was hiding even more rust, presumably where water had penetrated the sealant. So the welder came out yet again resulting in more patches than a patchwork quilt.
My second tip to anyone contemplating a chassis restoration is carry out the clean up operation before starting any repair work as you may end up changing your mind regarding the suitability of the chassis for restoration.
Unfortunately when completing a couple of the outriggers I did find small bad areas on the main chassis rails but I was now able to cut out the bad metal and weld in plates to make good the chassis. Thankfully this rot wasn’t bad by any means, otherwise I would have needed to source another chassis. Once a plate was in place I could temporarily clamp on a new outrigger using a large G-clamp. Following some very careful measurements I began welding the new outrigger in place, starting with just a couple of tack welds until I was satisfied with the positioning. This was followed by welding everywhere the outrigger contacted the chassis, including the inner edges to be absolutely certain these weren’t going to fall off.
I then repeated the same process for the remaining four outriggers. My welding skills leave a lot to be desired but I am satisfied these outriggers are going nowhere soon! Once all outriggers were welded in place I was able to fit the side rails. After checking the measurements against the detailed drawings I was able to weld the new side rails in place.
The next task is to remove all the underseal and sticky oil from the main chassis rails. This is a horrible job as it’s extremely messy and there’s no quick way I know of. I used a blowtorch to soften the underseal (risky process, better to use a hot air gun) and ordinary paint scraper to start removing it, It soon became obvious that the underseal was hiding even more rust, presumably where water had penetrated the sealant. So the welder came out yet again resulting in more patches than a patchwork quilt.
My second tip to anyone contemplating a chassis restoration is carry out the clean up operation before starting any repair work as you may end up changing your mind regarding the suitability of the chassis for restoration.
Once I was satisfied that all welding was complete I set about removing the remnants of underseal and cruddy oil with thinners. One word of warning regarding using thinners as a cleaning agent, make sure your cleaning equipment is well away from the car if like me you do any more welding – I ended up setting everything on fire with the flames very rapidly spreading towards my wooden garage, but luckily I had my fire extinguisher to hand for such an emergency. This little bit of advice may sound so very obvious but this one error left me standing in the middle of a pool of flaming thinners!
Once I could see every last bit of metal and was satisfied all rot had been dealt with I began the final removing of all surface rust using rotary wire brushes and the angle grinder before coating the bare metal with an anti-rust coating.
So with the chassis now prepared for painting, and as I was less concerned about the quality of the finish than I was about rust returning (most of the chassis will be out of sight anyway), I decided to apply the primer/undercoat by brush to help ensure a good thick coat which will hopefully help keep rust at bay. The odd bits that couldn’t be reached by brush were sprayed with aerosol anti-rust primer, particularly around the diff’ area which is impossible to reach once everything is reassembled.
Once I could see every last bit of metal and was satisfied all rot had been dealt with I began the final removing of all surface rust using rotary wire brushes and the angle grinder before coating the bare metal with an anti-rust coating.
So with the chassis now prepared for painting, and as I was less concerned about the quality of the finish than I was about rust returning (most of the chassis will be out of sight anyway), I decided to apply the primer/undercoat by brush to help ensure a good thick coat which will hopefully help keep rust at bay. The odd bits that couldn’t be reached by brush were sprayed with aerosol anti-rust primer, particularly around the diff’ area which is impossible to reach once everything is reassembled.
On now to the final stage of spraying the top coat. I’ve never sprayed before, other than with aerosol paint, so I approached this with some trepidation but as it turned out I needn’t have worried as it’s not as difficult as I imagined. I won’t be going in to any detail here as this is a subject in its own right and there are other people who know far more than I do on the subject, instead I will just concentrate on the logistics of the task.
I had already bought myself a compressor, spray gun, face mask, overalls, etc, the only thing I didn’t have was a spray booth. I couldn’t use the garage as it was packed to the rafters with the dismantled Herald so I decided to buy a 6mtr x 3mtr marquee off eBay. If anyone is thinking of re-spraying a car then I suggest you consider doing the same, it really is worth the additional cost to create a clean dust-free spray booth well away from the house, which can be erected in a few minutes, and is easily packed away ready for next time.
Choosing the colour wasn’t a difficult task as I wanted to take the opportunity to follow the original factory colour scheme. I was advised that the chassis would have originally been sprayed in the same colour as the primary colour of the bodywork, which in my case was Conifer Green. I managed to find a local paint supplier who, despite popular belief following recent legislative changes, is still able to supply me with cellulose paint mixed to any colour I need.
So with everything ready I got on with the spraying, which went pretty well and with no major issues, the end results of which can be seen in the photograph.
I had already bought myself a compressor, spray gun, face mask, overalls, etc, the only thing I didn’t have was a spray booth. I couldn’t use the garage as it was packed to the rafters with the dismantled Herald so I decided to buy a 6mtr x 3mtr marquee off eBay. If anyone is thinking of re-spraying a car then I suggest you consider doing the same, it really is worth the additional cost to create a clean dust-free spray booth well away from the house, which can be erected in a few minutes, and is easily packed away ready for next time.
Choosing the colour wasn’t a difficult task as I wanted to take the opportunity to follow the original factory colour scheme. I was advised that the chassis would have originally been sprayed in the same colour as the primary colour of the bodywork, which in my case was Conifer Green. I managed to find a local paint supplier who, despite popular belief following recent legislative changes, is still able to supply me with cellulose paint mixed to any colour I need.
So with everything ready I got on with the spraying, which went pretty well and with no major issues, the end results of which can be seen in the photograph.
In my next update I’ll be covering the chassis re-build, which is something I’m really looking forward to as this is where the shiny bits start to come together and I can take a break from sanding, grinding, and welding.
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