1965 Triumph Bonneville TT
- Thread starter Number 6
- Start date
The Mikeyboy of old Triumphs!
Number 6
Registered user
Tank Troubles. 
1.
I wasn't 100% happy with the TT tank so I sanded it all back and started afresh. I got it nicely primed and put on the Silver on the lower half, then did the silver basecoat under the blue, all good so far. I then applied the Pacific Blue top coat and for some reason I put way too much on and it was an awful patchy mess and way too dark.
So after a good bollocking I sanded it all back yet again and made myself take the time to do it right. I was shitting myself when putting on the Pacific Blue, it's so easy to get too much on, it's a Candy paint and the blue is translucent so the silver metallic basecoat can be seen. It looks fantastic when done right but shit when it's wrong. Anyway it was third time lucky, I finished it last Saturday and the Clearcoat has been curing for week and is now hard enough to polish. I'll put up some pictures next week, the colour is amazing, it waas worth doing it three times to get the end result. 
2.
Whilst the TT tank was curing I made a start on the '68 TR6C tank. I bought this off Ebay from the US a few years ago, it's a really solid and rust-free tank but has had a filler repair on the front corner which had started to fail.
I think the blue paint was rattle-can, it didn't take kindly to the cellulose primer I put over it so had to go carefully building up light coats to avoid it reacting and wrinkling.
Eventually I got a beautifully flat primer finish but took no pictures sorry.
Then I did the centre silver stripe and then the gold pinstripes, it's all paint!
Then I put on the Riviera Blue which is just a one-coat metallic, much easier to do than the Candy paints, left it for a day and then clear coated it. It looked fantastic when done.
I was well chuffed with it, at last something had gone right. Or so I thought.
1.
I wasn't 100% happy with the TT tank so I sanded it all back and started afresh. I got it nicely primed and put on the Silver on the lower half, then did the silver basecoat under the blue, all good so far. I then applied the Pacific Blue top coat and for some reason I put way too much on and it was an awful patchy mess and way too dark.
So after a good bollocking I sanded it all back yet again and made myself take the time to do it right. I was shitting myself when putting on the Pacific Blue, it's so easy to get too much on, it's a Candy paint and the blue is translucent so the silver metallic basecoat can be seen. It looks fantastic when done right but shit when it's wrong. Anyway it was third time lucky, I finished it last Saturday and the Clearcoat has been curing for week and is now hard enough to polish. I'll put up some pictures next week, the colour is amazing, it waas worth doing it three times to get the end result. 2.
Whilst the TT tank was curing I made a start on the '68 TR6C tank. I bought this off Ebay from the US a few years ago, it's a really solid and rust-free tank but has had a filler repair on the front corner which had started to fail.
I think the blue paint was rattle-can, it didn't take kindly to the cellulose primer I put over it so had to go carefully building up light coats to avoid it reacting and wrinkling.
Eventually I got a beautifully flat primer finish but took no pictures sorry.
Then I did the centre silver stripe and then the gold pinstripes, it's all paint!
Then I put on the Riviera Blue which is just a one-coat metallic, much easier to do than the Candy paints, left it for a day and then clear coated it. It looked fantastic when done.
I was well chuffed with it, at last something had gone right. Or so I thought.
Number 6
Registered user
Tank Troubles.
3.
I then made a start on the '67 TR6C tank which had some horrible threaded bar brazed into the front mountings.
I also knew that there was what appeared to be a large grub screw protruding into the inside of the tank from the right hand mounting, god knows what someone had done there. I cut off the threaded bar and realised that this needed some serious work to put it right.
I decided to take some measurements from the tank mountings on the frame to get the centres right. I measured the frame but couldn't get an accurate result, it was about 5" between centres. I then remembered that the TR6C tank that I had just finished was hanging up curing so I went and measured that. 4 3/8"! WTF!!! I re-checked the frame, 5". I checked the tank that I was working on, no way were the centres 4 3/8" they were definitely 5". I then realised that it was in fact a 500 tank and not a 650. Again, I'd bought it from Ebay USA, it was definitely advertised as T120/TR6 tank and I paid a lot for it, over £400 including shipping and import fees. So it won't fit. Fuck. Anyone want to buy a T100C/Daytona tank in Riviera Blue and Silver Sheen?
3.
I then made a start on the '67 TR6C tank which had some horrible threaded bar brazed into the front mountings.
I also knew that there was what appeared to be a large grub screw protruding into the inside of the tank from the right hand mounting, god knows what someone had done there. I cut off the threaded bar and realised that this needed some serious work to put it right.
I decided to take some measurements from the tank mountings on the frame to get the centres right. I measured the frame but couldn't get an accurate result, it was about 5" between centres. I then remembered that the TR6C tank that I had just finished was hanging up curing so I went and measured that. 4 3/8"! WTF!!! I re-checked the frame, 5". I checked the tank that I was working on, no way were the centres 4 3/8" they were definitely 5". I then realised that it was in fact a 500 tank and not a 650.
Again, I'd bought it from Ebay USA, it was definitely advertised as T120/TR6 tank and I paid a lot for it, over £400 including shipping and import fees. So it won't fit. Fuck. Anyone want to buy a T100C/Daytona tank in Riviera Blue and Silver Sheen?
Number 6
Registered user
3. Continued.....
After cutting off the threaded bar I had to work out exactly what had been done to the tank. I'd already seen a grubscrew poking into the tank so I guessed that someone had somehow punctured the tank either by tapping out the mounting hole threads and going too deep or by using overlength bolts which has the same effect. It's a common problem on old Triumph tanks, the mounting holes are not blind and it's all too easy to break through into the tank itself. This tank had obviously been 'repaired' by brazing in steel discs which were tapped to take the threaded bar which weren't even perpendicular or even parallel to each other.
I drilled through one of the discs and managed to break it free with a stud extractor, I could then see the grubscrew which had been inserted into the tank to plug the hole which someone had made.
The second one was harder to remove as there was much more braze around the disc.
I chain drilled around it with firstly a 3mm drill bit, then a 4mm and managed to break it free whereupon I saw another grubscrew threaded into the tank. I knew I would have to either weld or braze the tank to fix it properly but I was concerned as to how the grubscrews had been sealed into the tank. I needn't have worried, when I started to clean up the hole the first grubscrew just fell into the tank, it wasn't sealed with anything! What was the fucking point of that??? Someone had gone to a lot of trouble to 'fix' this tank but then did something completely stupid. I then tried the other grubscrew and it too just basically fell out. Unbelievable.
I then cleaned up the ragged edges of both holes. One of the offending grubscrews pictured.
I had a plan in mind as to how to remake the mounts but I also need to fill the rather large holes in the tank as well.
I found some 1 1/4" round bar which was a perfect size to make the new mounts from.
So I turned up a couple of pieces on the lathe, and tapped them 1/4 x 26 CEI to suit the original tank mounting bolts.
Next I had to fix the holes. I decided to Mig weld them, the first one (on the right) was rather tricky and blew through immediately. I turned down the settings on the welder and went very carefully gradually filling the hole, the second one (on the left) was much neater. I then dressed the welds back with the die grinder to make room for the new threaded inserts.
Then to make doubly sure that there would be no leaks, I brazed over and around the welds.
In order to get the correct 5" between centres spacing and to keep them at the same height I made a small jig to hold the inserts.
I tacked the inserts in place with the Mig welder then, I removed the jig and brazed them. Brazing gives a much stronger joint in this situation with the thin sheet steel of the tank and the thicker inserts, as the braze penetrates deep down into the gap between the parts.
After cutting off the threaded bar I had to work out exactly what had been done to the tank. I'd already seen a grubscrew poking into the tank so I guessed that someone had somehow punctured the tank either by tapping out the mounting hole threads and going too deep or by using overlength bolts which has the same effect. It's a common problem on old Triumph tanks, the mounting holes are not blind and it's all too easy to break through into the tank itself. This tank had obviously been 'repaired' by brazing in steel discs which were tapped to take the threaded bar which weren't even perpendicular or even parallel to each other.
I drilled through one of the discs and managed to break it free with a stud extractor, I could then see the grubscrew which had been inserted into the tank to plug the hole which someone had made.
The second one was harder to remove as there was much more braze around the disc.
I chain drilled around it with firstly a 3mm drill bit, then a 4mm and managed to break it free whereupon I saw another grubscrew threaded into the tank. I knew I would have to either weld or braze the tank to fix it properly but I was concerned as to how the grubscrews had been sealed into the tank. I needn't have worried, when I started to clean up the hole the first grubscrew just fell into the tank, it wasn't sealed with anything! What was the fucking point of that??? Someone had gone to a lot of trouble to 'fix' this tank but then did something completely stupid. I then tried the other grubscrew and it too just basically fell out. Unbelievable.
I then cleaned up the ragged edges of both holes. One of the offending grubscrews pictured.
I had a plan in mind as to how to remake the mounts but I also need to fill the rather large holes in the tank as well.
I found some 1 1/4" round bar which was a perfect size to make the new mounts from.
So I turned up a couple of pieces on the lathe, and tapped them 1/4 x 26 CEI to suit the original tank mounting bolts.
Next I had to fix the holes. I decided to Mig weld them, the first one (on the right) was rather tricky and blew through immediately. I turned down the settings on the welder and went very carefully gradually filling the hole, the second one (on the left) was much neater. I then dressed the welds back with the die grinder to make room for the new threaded inserts.
Then to make doubly sure that there would be no leaks, I brazed over and around the welds.
In order to get the correct 5" between centres spacing and to keep them at the same height I made a small jig to hold the inserts.
I tacked the inserts in place with the Mig welder then, I removed the jig and brazed them. Brazing gives a much stronger joint in this situation with the thin sheet steel of the tank and the thicker inserts, as the braze penetrates deep down into the gap between the parts.
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Number 6
Registered user
The finished article, I'm well pleased with it. It's completely leak proof, has great strength and looks just like the original mountings. Just a little more tittivating tomorrow to blend it all in.
Great work @Number 6 and thanks for taking the trouble to write and post all this. Enjoying it thoroughlyThe finished article, I'm well pleased with it. It's completely leak proof, has great strength and looks just like the original mountings. Just a little more tittivating tomorrow to blend it all in.
View attachment 430965
View attachment 430966
View attachment 430967
Superb write up and pics.
I am in awe of your skills
I am in awe of your skills
An absolutely perfect job Andy.
I've only seen work that good a few times, either in Aerospace or Racing circles. Usually by people with many years of experience
A perfect 10
I've only seen work that good a few times, either in Aerospace or Racing circles. Usually by people with many years of experience
A perfect 10
Number 6
Registered user
Tank Troubles.
......... I measured the frame but couldn't get an accurate result, it was about 5" between centres. I then remembered that the TR6C tank that I had just finished was hanging up curing so I went and measured that. 4 3/8"! WTF!!! I re-checked the frame, 5". I checked the tank that I was working on, no way were the centres 4 3/8" they were definitely 5". I then realised that it was in fact a 500 tank and not a 650.
Panic over!
After much thought and checking pictures of T00 tanks online, I realised that it wasn't a T00 tank as the mountings are completely different. This was a T120/TR6 tank in all respects bar the width of the front mounting holes. These are threaded 5/16 x 24 UNF meaning it was off a 1969-70 bike but why were the hole centres too close together?
This morning I put the tank side by side with the black tank and compared them. Everything was identical except for the mounting holes and also the frame tunnel was a little narrower.
Then I remembered about the body filler on the right-hand side of the tank, it had obviously had a hard knock at some point in it's life, could it possibly have been hard enough to squash the two sides of the tank together?
The body filler...
If I couldn't fix it the tank was basically scrap so nothing ventured nothing gained. I made a spreader tool out of M16 threaded bar, a couple of nuts and washers and two bits of 10mm steel flat bar which I wrapped in gaffa tape to protect the paintwork.
This was the measurement I started with, 4 5/8" so 3/8" (10mm) too close together.
I placed the spreader in the frame tunnel and slowly wound the nuts out to push the two halves of the tank apart.
I then wound the nuts back in and the tank sprang back slightly but it was definitely better, so I repeated the process and this was the result........5" bang on!
No damage to the paintwork at all, everything just as it should be, Happy days.
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Top man 
That is a great result on both tanks, a proper old school engineering approach to fixing real problems, so much better than just throwing money at trying to get hold of another one.
I wondered if the paint would crack, but obviously done carefully it was okay.
Glad this worked out for you, as the blue n silver looks great….. a great job number 6!
Enjoying your updates….. please continue
Glad this worked out for you, as the blue n silver looks great….. a great job number 6!
Enjoying your updates….. please continue
Number 6
Registered user
I wondered about the paint cracking myself but there was no other option. I've checked all over the tank and there's no signs at all of any cracking or distortion, I think that because the paint was 'dry' but not fully cured it prevented any problems. (the 2 pack Clear Coat takes 7 days to fully harden) Even if it did crack the paint I've still now got a perfectly good tank to re-paint, if I had to get another tank I'd still have to paint that one so at the end of the day there was nothing to lose.
What surprised me was how little effort it required to spread the tank by 3/8", just a few light turns on the spanner was all it needed.
Hi, I really like that tank, the silver and then gold pinstripes look brilliant. Was this a colour option on the original? I have a Bonnie 790 (heretic!) with a plain blue tank and was thinking about something more interesting on the tank, this scheme would work well as the mudguards are silver too. Cheers 
John B
John B
Number 6
Registered user
Hi John, yes it was the original colour scheme for the 1968 TR6C. Riviera Blue with a Silver Sheen centre stripe and Gold pinstripes.Hi, I really like that tank, the silver and then gold pinstripes look brilliant. Was this a colour option on the original? I have a Bonnie 790 (heretic!) with a plain blue tank and was thinking about something more interesting on the tank, this scheme would work well as the mudguards are silver too. Cheers
Number 6
Registered user
Sorry for the lack of updates but I haven't been slacking, honest. Once again the petrol tank caused me grief. When polishing up the clear coat one side of the tank didn't seem to be coming to a nice glass-like finish and fearing I was maybe going through to the paint underneath I decided to apply another few coats of clear-coat. The result was a disaster, for some reason the new clearcoat reacted very badly with the underlying cellulose paint and wrinkled terribly, I didn't take any pictures but it was horrible. There was nothing to do but sand it all back to primer once again, I took a chance on only doing the one side of the tank hoping that I could get a good match to the other side but to be honest by this point I was beyond caring. I fully expected to take the whole tank back to primer and start completely afresh for the fourth time. As luck would have it everything turned out well and it is now better than it ever was. After another week curing I polished it again and added the centre-strip, badges, knee grips and rack. It looks amazing, the pictures really don't do it justice it's a beautiful colour especially in direct sunlight where the metallic basecoat shines through and don't forget that this was in 1965.
Compared to the 1968 TR6C tank in Riviera Blue. In reality they are subtly different, my favourite is definitely the '65 Pacific Blue.
On the bike.
I'd been wanting to get the carburettors on but needed to replate the inlet stubs. These aren't the same ones but shows the condition they were in beforehand.
My plating tank set-up, it's a Nickel and Zinc process.
The finished items, they came out really well once I'd got the correct amps dialled in.
And on the bike with new and correct Amal Monobloc 389/95 carbs.
I wasn't totally happy with the timing cover which I'd polished up previously so today I had another go at it. I wanted to preserve the dents and scrapes and just remove the pitting but unfortunately that wasn't possible. I also replaced the data plate which was a bit tatty. Before :-
Then after the first refinish :-
The easiest way to remove the fixings, which are hammer-drive scews, is to carefully prise away the old plate which leaves more of the screws to get a grip of. With some heat applied to the cover they can then be gripped with pliers and wound out anti-clockwise.
The new screws :-
Compared to the 1968 TR6C tank in Riviera Blue. In reality they are subtly different, my favourite is definitely the '65 Pacific Blue.
On the bike.
I'd been wanting to get the carburettors on but needed to replate the inlet stubs. These aren't the same ones but shows the condition they were in beforehand.
My plating tank set-up, it's a Nickel and Zinc process.
The finished items, they came out really well once I'd got the correct amps dialled in.
And on the bike with new and correct Amal Monobloc 389/95 carbs.
I wasn't totally happy with the timing cover which I'd polished up previously so today I had another go at it. I wanted to preserve the dents and scrapes and just remove the pitting but unfortunately that wasn't possible. I also replaced the data plate which was a bit tatty. Before :-
Then after the first refinish :-
The easiest way to remove the fixings, which are hammer-drive scews, is to carefully prise away the old plate which leaves more of the screws to get a grip of. With some heat applied to the cover they can then be gripped with pliers and wound out anti-clockwise.
The new screws :-
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Number 6
Registered user
Timing cover polished once again and Data plate fitted :-
and refitted, it looks much better now. (look at the state of that gear lever rubber, it's brand new. Modern rubber is just rubbish, it cracks and perishes in no time at all. )
I've fitted the new carbs and twistgrip and made up new throttle cables. The handlebar grips are actually Yamaha TZ but they look the part and are really comfortable, I use them on all my old bikes. The kill switch (next to the brake lever) is the original item for the Energy Transfer ignition as fitted in 1965. Boyer-Bransden say that it will work with their Electronic Ignition system but I'm going to ring them next week to confirm this.
and refitted, it looks much better now. (look at the state of that gear lever rubber, it's brand new. Modern rubber is just rubbish, it cracks and perishes in no time at all.
)I've fitted the new carbs and twistgrip and made up new throttle cables. The handlebar grips are actually Yamaha TZ but they look the part and are really comfortable, I use them on all my old bikes. The kill switch (next to the brake lever) is the original item for the Energy Transfer ignition as fitted in 1965. Boyer-Bransden say that it will work with their Electronic Ignition system but I'm going to ring them next week to confirm this.
Number 6
Registered user
AS the TT had no battery and associated electronics there was no battery tray fitted. I needed somewhere to mount the Boyer Power Box and Ignition module so I bought a pair of mounts for the road-going 1965 T120. These also provide a mounting point for the side panel.
I then needed to fabricate some sort of tray to house the Boyer components. I had some left-over aluminium angle section that could do the job, I cut it into four equal pieces and bolted it together.
I then made up some straps to hang the tray from the brackets in the first picture. I thought I had some stainless steel flat bar but unfortunately didn't have enough. I did however have a piece of scabby aluminium plate. I cut off four strips with a Jigsaw, and filed them flat and parallel.
As it turned out I only used three of them, there's not much weight to support and three straps would be plenty.
I also modified the tray to accomodate both boxes and mounted the Power Box on rubber washers. The ignition box sits on a self-adhesive foam rubber strip and is secured with a cable tie.
The tray mounted to the battery carrier straps, which are also rubber-mounted. So, all in all there are three separate places where the ignition and power boxes are rubber mounted, vibration shouldn't be a problem!
The M6 threaded post with the nuts and washers is an earth terminal, all the positive (red) wires will connect to this via ring terminals along with an earth lead fastened directly to the engine. It's not far from being a runner now, we're away on the GSA again in 2 weeks, hopefully I'll have it fired up before then.
I then needed to fabricate some sort of tray to house the Boyer components. I had some left-over aluminium angle section that could do the job, I cut it into four equal pieces and bolted it together.
I then made up some straps to hang the tray from the brackets in the first picture. I thought I had some stainless steel flat bar but unfortunately didn't have enough. I did however have a piece of scabby aluminium plate. I cut off four strips with a Jigsaw, and filed them flat and parallel.
As it turned out I only used three of them, there's not much weight to support and three straps would be plenty.
I also modified the tray to accomodate both boxes and mounted the Power Box on rubber washers. The ignition box sits on a self-adhesive foam rubber strip and is secured with a cable tie.
The tray mounted to the battery carrier straps, which are also rubber-mounted. So, all in all there are three separate places where the ignition and power boxes are rubber mounted, vibration shouldn't be a problem!
The M6 threaded post with the nuts and washers is an earth terminal, all the positive (red) wires will connect to this via ring terminals along with an earth lead fastened directly to the engine. It's not far from being a runner now, we're away on the GSA again in 2 weeks, hopefully I'll have it fired up before then.
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