Topic: 1972 CB750 Steampunk(ish) Bobber Thing

[754]

Thereis a thread on main topic about it ...bottom of page 2.... Sohc 4 bikes,  ..title frame mods 750 view the last few pages..

[Noddy78]

Aha, got it, Thanks mate. Looks like a simple, elegant solution. I reckon there'd be enough meat on the current frame for it to work, what do you think? I'll check it for roundness too and get back to you.

[Retro Rocket]

I have one Of Franks frame kits Noddy, they are very well made and easy to use...

[754]

Where did you want to mount your ignition switch, stock location may be out unless you weld in a short piece.

[Noddy78]

Where did you want to mount your ignition switch, stock location may be out unless you weld in a short piece.

No worries there, the ignition switch will be miles away!

[DustyRags]

Ah, I love this place! No fear of dogpiling idiots, but when the wrenches hit the counter, everyone jumps in to help. Good show, lads, good show! *golf clap*

[Noddy78]

Well we seem to have made it back to civility somehow, not sure how long it'll last now though... best look away Terry (don't say I didn't warn you)! 





Too dumped?


The carnage:


Though if nothing else, got plenty of spare bits if you need them...

[RobbyD]

Wow, just looked over your build and have never seen so much hate with a build thread. 

Hats off to you for keeping with it.  Way I see it, it's your bike, your money, your time so you can do whatever you want with it.  I can appreciate stock restored bikes but keeping anything stock has never been me either, I don't want the same bike someone else has.  Not a fan of bobbers or choppers but I can also appreciate the work that went into them also.

Keep up the good work man and stick with it. 

[calj737]

How are you planning to join the new subframe to the top section? I see a gusset tacked on, but is that your permanent intention?

[Terry in Australia]

Well we seem to have made it back to civility somehow, not sure how long it'll last now though... best look away Terry (don't say I didn't warn you)! 





Too dumped?


The carnage:


Though if nothing else, got plenty of spare bits if you need them...

Looking good Noddy, I've seen those hardtail kits before and they seem to work OK, so it should be fine. I think I'll remove my earlier posts, it looks like you are the real deal, keep up the good work. Cheers, Terry.

[Noddy78]

How are you planning to join the new subframe to the top section? I see a gusset tacked on, but is that your permanent intention?

Not tacked up yet, just sitting there to see how it's looking. But yep, it's a TC Bros hardtail, so supposedly just welds up via that gusset and the plates at the bottom. Seems like it'll do the job ok, but I might mess with it a bit to make the joins a little nicer. The welding bits will have to wait until I get the new house/workshop though probably... if I can wait that long.

In the meantime...



It was just all bogged up with filler, without all of the rust taken out first by the looks of the state it was in.

And I've also been playing with what I want to with the frame. I was intending to go raw steel, but after a bit of playing around, I'm now thinking gun-bluing the whole thing could be cool, then hit it with some Gibbs Brand penetrant, so darkening it up a bit, but keeping the raw steel feel. Did a bit of a test tonight:

Raw:


Blued:


Hard to get the effect across in pictures, but I think it looks great. Dead easy, and adds another layer of rust protection but keeps the raw metal vibe I want to go with.

[calj737]

 I think bluing would rust very quickly if you're referring to the same process a gunsmith uses. Additionally, to get a great lustre, you'll have to polish the frame to a near mirror finish. Any sweat or acid or rain or moisture on that bluing, and you'll have rust within hours.

Rotten luck about those mounting brackets.

[Noddy78]

Yeah, it's a gun-smithing cold blue, but I'm not really using for the rust protection, that's what the Gibbs Brand stuff is supposed to do (though haven't tried it yet) but the blue should help to some degree. Given I was planning on raw steel, the bluing certainly can't hurt. I'm not really going for lustre either, patina is the order of the day here.

[754]

Given the state of the frame, nobody should complain that you cut it up. Check closely your lower frame rails around. The sidestand area..another area rust is a problem.
I have never liked pressure washing bikes, can get in your wheel  bearings, forks, and looks like into the frame too..

[welard]

Just joined the thread Noddy....my compliments on your previous 350 project, which seems a walk in the park compared to the derision you've suffered on this project.

I'm only new here myself and am in the planning stages of a build, but with that kind of welcome I'm not sure I would have persisted....true grit on your part....and a proper doff of the cap to Terry...a proper bloke, quite happy and quick to provide his immense experience (and from what I gather, generous nature) to your project, once you've demonstrated your bona fides.

Looking forward to more brass stuff.

[Noddy78]

Well, I wasn't expecting that! The results after a day sitting in a bucket with a salt-water solution sprayed on it:

Raw:


Blued:


I thought it might help a little, not hinder! Got some Gibbs Penetrant on order now, so we'll see what that does for it.

Just joined the thread Noddy....my compliments on your previous 350 project, which seems a walk in the park compared to the derision you've suffered on this project.

Yeah, t'was a very different reaction that's for sure. I'm not sure what about Isabel meant it would be assumed I wasn't the 'real deal' on this one from the start, but I digress... Not that I'm even sure I am the real deal... Just a man... in front of a forum... asking them to love him...

Looking forward to more brass stuff.

Done. No laughing at the skinny white legs...

[Terry in Australia]

Yep, what's been said about the gun blue is correct, it'll rust in a heartbeat. I wonder though, if you could clear coat (or even clear powdercoat) over it?

The rust in your frame is common, usually on the left (sidetand) side,and actually caused by dirt and chain lube lodging in the gaps between the overlapping plates around the rear engine mount/swingarm pivot and not allowing water to drain out.

As Frank said, check your lower frame rails for rust holes (use something sharp and have a poke around) because they usually go as well. Cheers, Terry.

[dave500]

if you want more brass I have an old brass temp guage if you want it,ill get a photo in a day or two I have it at work if its still there and have a day off now.

[Noddy78]

Yep, what's been said about the gun blue is correct, it'll rust in a heartbeat. I wonder though, if you could clear coat (or even clear powdercoat) over it?

Yep, that's definitely one of the options I was considering. Though I've read a bit about the problem with clear powdercoat and clear paint in that if any moisture gets trapped under there it'll rust underneath the coating. I'll see what this Gibbs stuff does, apparently the hot-rodders swear by it, so I'll give it a crack and see how it holds up to the salt-water bucket test.

The rust in your frame is common...

Yep, kickstand side it is. also looks to be starting on the other side too. The previous owner's judicious use of body-filler extended to filling up the drain holes in the motor mounts, but at least he left the frame hole in there, so the lower frame rails are pretty good, it's actually the top of the rail where the water sat inside the motor mount that's gone (and the motor mounts). Will probably have to get the pros in to see if they can fix this one up, beyond my meagre abilities I think.

if you want more brass I have an old brass temp guage if you want it,ill get a photo in a day or two I have it at work if its still there and have a day off now.

Awesome, I'd love to check it out. Cheers.

[calj737]

May I ask, why in the world would you immerse something in salt water for a day to test corrosion resistance? Very few things would withstand that unless fully treated inside and out with an impregnated layer, and bluing is not among them.

Cold bluing or hot bluing depend on an absolutely clean surface to start with. Then, the finish is extremely susceptible to corrosion from the slightest and briefest of contact. It must be cleaned or wiped down promptly else it will rust. Guaranteed.

Anyone with firearms experience will tell you that rifle or shotgun barrels wipe their barrels down after handling for this very reason.

I am unfamiliar with the Gibbs stuff, but if it is "wiped or sprayed" on, it will not adhere permanently and thus it will fail. When it does, rust will appear, perhaps in an unnoticed place too.

If a unique finish is something you seek, try a bit of experiementing with this: polish that piece that you blued back to raw with as high a polished finish as yo can endure. Then, using Acetylene, heat it from within to discolor it. When cooled, handle only with clean clothes, and powder coat clear or paint clear over it. It might just retain enough of the heat discoloration to give you what you need. It would work better with CroMo pipe or stainless, but you might just get there without distorting the tubing strength.

[SOHC4 Cafe Racer Fan]

Another antiquing technique is to paint the frame the color of the desired patina and then sand off portions of it - and then clear coat it to preserve the look.

[sulphurdave]

Subscribed

[Retro Rocket]

May I ask, why in the world would you immerse something in salt water for a day to test corrosion resistance? Very few things would withstand that unless fully treated inside and out with an impregnated layer, and bluing is not among them.

Cold bluing or hot bluing depend on an absolutely clean surface to start with. Then, the finish is extremely susceptible to corrosion from the slightest and briefest of contact. It must be cleaned or wiped down promptly else it will rust. Guaranteed.

Anyone with firearms experience will tell you that rifle or shotgun barrels wipe their barrels down after handling for this very reason.

I am unfamiliar with the Gibbs stuff, but if it is "wiped or sprayed" on, it will not adhere permanently and thus it will fail. When it does, rust will appear, perhaps in an unnoticed place too.

If a unique finish is something you seek, try a bit of experiementing with this: polish that piece that you blued back to raw with as high a polished finish as yo can endure. Then, using Acetylene, heat it from within to discolor it. When cooled, handle only with clean clothes, and powder coat clear or paint clear over it. It might just retain enough of the heat discoloration to give you what you need. It would work better with CroMo pipe or stainless, but you might just get there without distorting the tubing strength.

Cal, the Gibbs is a penetrant and is absorbed by the metal, great stuff...

http://www.roadsters.com/gibbs/

[calj737]

It surely seems to be a wonder-drug type of product. I wonder could you blue over the Gibbs? If so, that might be an approach? Or teat with Gibbs after bluing then re-test?

I'd love to see something treated with Gibbs be immersed in salt water and determine if it won't rust?

[Noddy78]

May I ask, why in the world would you immerse something in salt water for a day to test corrosion resistance?

I'd love to see something treated with Gibbs be immersed in salt water and determine if it won't rust?

I assume you've answered your own question there? And I think may have misunderstood me. I didn't soak it underwater in salt water, I put the part in a bucket, and sprayed it with a demisting sprayer with salt water over the course of a day. So the bucket bit is not really that important, it just keeps the general area salty-moist. Mmm Salty Moist.

I was planning to Blue then Gibbs, I would assume if the Gibbs stuff works the way it's supposed to that the Blue wouldn't take (given it's a form of rust)? But I'll try both ways!