1967 V700 Corsa-Record

[Turin]

bump

[cliffrod]

bump

Thanks, man.  I need a bump.....

As a quick update, I've been making some progress on the system.  Doing the metalshaping for a seat for a friend's RD350 "real quick" back in Nov clarified that some old injuries will no longer tolerate such things like theyooo did years ago...  Some changes in method are helping.  This seat is a trial run for my Guzzi tank, as the rear hump is very similar to the rear half of the tank.









More shop equipment has been resolved, paid for, moved in, new LED lighting in both buildings and more.  The preferred method for welding aluminum sheet is oxygen/hydrogen gas welding.  there are many benefits so I decided to assemble a rig.   Finally got the last of my gear, including special low pressure regulators rebuilt in Pheonix, last month.

All of this has been happening during a lot of family stuff with my uncle's estate resolution & eldercare for my 79 yo mother plus our daughter's college details plus high school graduation and moving out last week. 

These things have made getting an extended amount of time in shop difficult.  Now we're home, much is done and I'm anxious to get some shop time building bike parts around "normal" stuff.  Spending some time oxy/hydrogen welding aluminum is first on the list so I can wrap up this RD seat.  A friend is having a metal meet later this summer and I want to have more done before then.

I have been able to identify the clip ons on the original Record bikes as Menani clip ons.  Just a little detail.  They aren't made anymore, but are available in reproduction.

[Canuck750]

You sir have some impressive metal working skills!

The preferred method for welding aluminum sheet is oxygen/hydrogen gas welding.

I have never even heard of this method, looking forward to seeing your progress.

[cliffrod]

Thanks, Jim.  The shaping on that seat was largely done with an arbor press, followed by English wheel.

Not sure about the chicken or the egg issues of what came first, but here's some background that I've learned about oxy/hydrogen in recent years-

Oxy/hydrogen was the method used for much of the aviation-related aluminum welding in the USA during WWII.  Hydrogen could be readily generated onsite so acetylene could be rationed for more important applications.  Acetylene is more versatile for a wide range of cutting, welding and brazing in general, so it remained/became the standard for many following the war. Oxy/Hydrogen is more of a dedicated specialty method.  Walk into a welding supply shop nowadays and ask about gas welding with Hydrogen- you'll get lots of ?!?? Looks and remarks.

Oxy/acetylene produces a very hot flame.  Once you melt the puddle, it's a WFO race to produce and complete the weld on thin aluminum sheet metal without failure.  Not impossible, but it's challenging.  The oxy/hydrogen flame is notably cooler and closer to the melting point of aluminum.  You can go slower and produce a better weld.  For thin material, gas pressure is in the 1-2psi range.  A trusted AV certified welder friend is welding 24g aluminum (!) with oxy/hydrogen. Very cool.  I would like to be able to do that....

Probably because of the higher temps, Oxy/acetylene requires greater use of flux, on both base metal parts and rod.  Oxy/hydrogen only requires the rod to be fluxed.  This means there less flux to clean/remove after welding, which is a big plus when welding enclosed pieces like tanks and sculptural work.  The flux aspect of welding aluminum parts is the scheduling buzzkill.  It's much like casting plaster models in studio- There's no way to skip or expedite the process or clean-up.  Miss anything and any remaining flux makes contaminated ferrous metal explode with rust & aluminum parts corrode.  Less flux clean-up will hopefully make it easier to fit the welding into my schedule.

The oxy/hydrogen flame is invisible (through the goggles) while burning, so produces no light.  The welding puddle/area must be lit by an external source.

In general, gas welding will produce the most equitable weld- it will be as strong, workable and homogenous as the parent metal.  This really matters when shaping metal.  TIG is good, but more likely to be harder/prone to cracking and produce minutely porous welds (especially tanks from thin aluminum) from what I'm told.  MIG is hard and brittle, no good for metal shaping.

I like gas welding better than other methods when it's practical.  I'm brand new at oxy/hydrogen, but see it as more practical for the range of sculpture work I want to do, including bikes.  Other people do it, so I'm sure I can.  At this point, I'm planning to make another seat & fender for my bike.  I'm not happy with the quality and know I can do better now.

[Canuck750]

Great explanation! thank you, very interesting.

Jim

[Rick4003]

Indeed, very nice work and good explanation on the oxy/hydrogen welding process. I just googled it also just because I'm curious, another reason added to the ones above for using hydrogen is that it is very pure in the gas form. Only water and heat will be created while burning. This is a definite plus while welding aluminium. It makes such a difference while TIG welding aluminium how clean you manage to get the metal before welding. I can imagine that acetylene burns dirtier than hydrogen.   

[cliffrod]

Discussing welding methods is often just another oil thread...   I'm not a pro, so only know so much. 

Pros who have access to better equipment than I do explain that a cross section of TIG-welded aluminum viewed under a microscope, regardless of the prep, will display minute porosity in the weld that will not be present in a comparable properly prepped gas weld.   A metal forum member recently posted about his frustration doing bike tanks with TIG. No matter how he prepped, he often had minute leaks to chase and resolve.  The previous explanation came (again) from two of the professional welders on the forum.  They suggested that he transition to gas welding as a solution, because the mentioned minute porosity of TIG was not atypical or a the result of user's flawed method.

Carving stone with loud pneumatic hammers has been my career for decades.  My ears already squeal all the time, so listening to a squealing TIG doing aluminum in my spare time is a drag.   The peace and quiet of gas welding and using the English Wheel to make shapes is great.  Producing a sound weld that is as soft as the parent metal is the goal.  Hard welds crack when worked and will mark the anvils & wheel on the English Wheel. The two methods work in perfect unison.  Very cool...

[Rick4003]

I can imagine it could turn out as a oil thread. Please post up your experience with the oxy/hydrogen welding setup, it does sound like a very good match for aluminium welding. For now I use my TIG welder as i don't have anything else that can weld aluminium. And oxy+acetylene/propane/hydrogen setup is on the wish list, but the cost of the bottles are putting that wish on a quite long term plan... The buzz of the TIG can be a little annoying but I find that I have gotten use to it.

Do you have any experience with sandbag + planishing hammer or have you always used the English wheel? An English wheel is probably out of the question for me as the workshop is tight enough as it is, but a pneumatic planishing hammer would be possible to store on the wall when not in use. And I could build one myself quite easily.

[cliffrod]

I can imagine it could turn out as a oil thread. Please post up your experience with the oxy/hydrogen welding setup, it does sound like a very good match for aluminium welding. For now I use my TIG welder as i don't have anything else that can weld aluminium. And oxy+acetylene/propane/hydrogen setup is on the wish list, but the cost of the bottles are putting that wish on a quite long term plan... The buzz of the TIG can be a little annoying but I find that I have gotten use to it.

Do you have any experience with sandbag + planishing hammer or have you always used the English wheel? An English wheel is probably out of the question for me as the workshop is tight enough as it is, but a pneumatic planishing hammer would be possible to store on the wall when not in use. And I could build one myself quite easily.

My metal shop,,which also serves as mechanical shop to keep everything from lawn mower to bikes to stone tools operational, is 20x30. Right now, with a car inside, it's too full.

My goal doing metal was to do it with fewer tools, partially because it fit my budget and partially because "real" metal working equipment has become very hard to find.  So I used hammers, a stump, shot bag and shop junk for the few small projects.  That's all I had. 

In 2008(?), there was an article in Street Rodder magazine about using an arbor press to shape metal.  A motorcycle fender can be shaped in 20 minutes.  Small wrinkles (tucks) are created and then pressed flat to shrink the metal.  It works so well it's hard to believe.  The limiting factor is throat depth, not tonnage. No noise at all, no power and very easy on your body. 

My 2ton arbor press, mounted on old cast iron stand-





For this seat hump, I made some simple dies with different radii out of firewood.  I turned them on my wood lathe, but they could easily be made by hand.





You can work against a small shot bag, hard plastic or anything appropriate for the desired effect for an anvil.  I decided to try some of the thick black urethane tube that I used to make the tank mounting bushings.  It has a central bore that is the same diameter of my tooling.









Using this setup, I formed the entire top piece of the seat hump with the plastic protective cover left on the aluminum during the process.  It you don't mark the metal during shaping, there's nothing to clean up later.   I did planish this part on the English wheel, but that could be done with patience by hand.













For a small shop with limited space, it's hard to beat an arbor press.  It makes no noise.  Tooling is very easy to make and it can do many things including shrinking.  My current rear fender was also made with an arbor press.

For years, I wanted a cast iron English wheel.  Fabricated English wheels are available in built or kit form.  The concern I have with many of the fabricated machines is cost vs resale.  They hold little value for resale and the final cost to have one working well often rivals a used "real" machine.  After 30 yrs of waiting and looking, I got my cast iron English Wheel from a Master Metalshaper named Peter Tommasini in AU.  http://www.handbuilt.net.au. He is a very important resource for many of us learning about the craft.  No games, foolish tricks or bad advice like many (most?) on the Internet and YouTube. Do what he says and it works.  His wheel is a fantastic tool to use.  I see it as a bank account.

just before and during -, I was fortunate to find great deals and have added a large Gairu (pullmax) reciprocating machine, a CP Fender Iron planishing hammer, a Pexto 13" bead roller, numerous stands plus an index milling machine and metal lathes to make my tooling.   After literally 30 yrs of going without, looking for good machines, collecting the equipment & materials to build substitutes in their absence and life in general, I suddenly have the shop I never imagined I would have.  I'm still working to get all operational and cleaning out everything else.  It's a slow process for a one-man operation.

The large hoop for the planishing hammer has been mounted on an old floor stand but I haven't used it much yet. 





I also mounted my small shrinker/stretcher on an old foot pedal floor stand and added compound action for increased leverage, based upon the design of vise grip locking pliers (someone else's idea, not mine)   It works ok but I need to correct the actuation geometry of mine for the best performance.









My bead roller, mounted but not yet powered, on a new old cabinet-





The last year has been very productive in terms of equipping my shop.  I haven't gotten much metal work done but i shouldn't have to equip my shop again..

If you decide to build a planishing hammer, it's important to understand that a normal cheap air chisel WON'T work very well.  I use air powered hammers for a living.   They are not all the same.  Buy a proper high quality air motor if you build one.  Peter now sells a kit to mount an air motor in one of his cast iron English wheel frames so it can be used as a power hammer.  I may make one now that I have machine equipment.  We'll see.

If you decide to buy one machine and like the planishing hammer approach, An acquaintance in EU has a machine named a MechHammer. https://www.mechammer.com It's really amazing how versatile it is, fully self contained and very small.   Ben is a great guy.

[cliffrod]

Figured I would do the gas welding in a separate post.  A gas welding rig is indispensable in my shop.  I use my oxy/acetylene torch all the time.  By comparison, I rarely use my TIG or stick welder unless I'm welding thick material.  The addition of an oxy/hydrogen rig is somewhat of a luxury, but should be worth it for the work I expect to do with it now that I'm ready to do more with aluminum.

There's been a lot of consolidation in the welding industry in recent years.  As a result, many good styles and quality brands have been discontinued.  Additional tips and service parts may not be readily available anymore.  So a bargain used torch may not be much of a bargain.  Do some research.

I've used a basic set of single stage regulators for 25 yrs that were fine for what I did.  Now that I'm trying to weld at such low pressures, I have added a pair of Victor VTS-250 two stage regulators.  Since the pressure is regulated in two stages, dropping pressure in the tank does not cause the same fluctuations in psi at the torch. The rebuilder recommended these Specific regulators because rebuild parts are still readily available.  He has also found these units can more easily achieve & maintain 1psi-2psi than the larger models.  He built these to operate up to approx 5psi, so they're very sensitive.  VTS-250 regulators are originally supplied with a letter suffix like A,B, C to denote the original pressure range of use.  A is the lowest psi.  But any VTS 250 gauge can be rebuilt to the desired specs.

For a torch, last summer I purchased a Meco Midget.  One renowned metal expert named Kent White has been pivotal in keeping this torch and related parts on the market.  https://www.tinmantech.com  Some people like other torches better, but this one is still 100% supported.  It wasn't designed as an aviation torch but has similar forward controls that don't get bumped as easily during use.  Most of the actual gas welding aviation torches have gone out of production.  For welding thin materials, especially when used with Kent's lightweight lead hoses, the Meco Midget is a very good torch.  But torch preference is another oil thread....   I have a favorite old Concoa/Airco torch (out of production) that welds fine with the proper tip.  But it has regular controls at the base and a little bump while welding always causes problems.  I have a victor J28 clone that I would like to buy more tips for....

If you gas weld very much, a gas saver shut off valve is a smart investment to save both fuel and time. Constantly relighting and adjusting a torch is a deal breaker when all you have to do is lift the torch off the hanger and light it without touching a knob to go back to work.

Setting up this oxy/hydrogen welding kit wasn't cheap. I figured around $1200 so far and still could use a few more bits.

[Rick4003]

Bugger I had written a long reply but it got lost. You will get a small resume instead

Great idea using an arbor press for shaping the metal, I have not seen it used in that way before. Found a few videos on it and it does looks like it works extremely well. I have to get myself an arbor press.

The Mechammer looks very nice as well and I like how they have used a sewing machine motor for the drive unit. Very clever idea. I looked up the price and unfortunately it is way out of my price range at +6000€. But I might give it a shot building one myself. There is a danish style planishing hammer that also uses and electro motor and an eccentric to create the movement of the hammer blow. Perhaps a hybrid could be made fairly easily. I do have a fully equipped machine shop after all

There is plenty of things I would like to have a gas welding setup to do, so at some point I will likely invest in a set of used bottles and a new set of torches. The ones I usually see for sale are often well past their best by date. Most looks like they have been abused by farmers for the last many decades.

Thank you very much for the great info and the good info contained in those posts and this whole thread!

[cliffrod]

Ben's Mechhammer isn't cheap, but the design is good to consider.  I was put off by the prices of many new and most used machines.    Fabricating what you need is an option.  Buying the parts, especially if you cannot do all the machine work, can quickly make that cheap route become expensive.  Be realistic about your budget.  For example- If you think it will cost X and take 6 months to complete the build, consider it will probably cost closer to 2x and take a year to be fully operational. then look at what can be bought with that budget.  That's basically what I did.  Keep saving, looking and learning.  Along the way, better opportunities were realized.

One consistent trait of many fabricated machines is flex because steel behaves differently than good cast iron. Flex isn't necessarily bad, but some types of flex are less desirable than other types.  It's something to be managed if you want consistent results.  Cast vs fabricated (especially regarding English Wheels) is a HUGE oil thread...

Until I bought these larger tanks last month, I've used 40cf tanks for decades.  The rules about owning & exchanging small tanks vs leasing large tanks and recertification of expired tanks vary here in the USA, mainly between welding supply shops.  It's good to ask the local shop to know what their rules are versus trusting what a couple of friends say.

[cliffrod]

Slowly creeping onward around life in general, yesterday I finally had to to begin practicing welding .063 thick 3003  aluminum with  oxy/hydrogen. Practiced another 10'-15' of bead today.    It's no magic bullet, but is far more tractable than the absolute race of welding aluminum sheet with oxy/acetylene.    I need to spend more time but am comfortable thinking that this will be a better method for my aluminum bike parts.

We've been discussing oxy/hyd welding on another forum.  It's relatively specialized and not as versatile as the more common oxy/acetylene gas welding.  Hydrogen requires dedicated equipment and has some unique requirements & characteristics that may not be not suitable for every shop.  If I could only have one rig, it would be oxy/acetylene. I plan to keep doing both on aluminum to become a better gas welder in general.

No pretty pics yet.  These welds either need careful Photoshopping or a lot more practice before I post them......

[cliffrod]

After some practice, I used my new oxy/hydrogen rig & welded up the RD350 cafe seat hump.  This is my first "real" part welded after doing a big pile of practice coupons.   There were a couple of bubblegums on one bead, but decent overall penetration and I'm pretty happy to be making progress. 

During recent weeks, I've learned that this 5000 series aluminum is more corrosion resistant than the 100 and 3003 series aluminum often used for shaped parts, so the mild grainy quality of the welds is probably related to the specific alloy.  New proper flux, proper spring water, proper neutral flame, proper psi and ratio, etc will not resolve it.





















This seat hump is specifically relevant to my Guzzi because this is essentially the same shape and pieces as the top rear half of my gas tank top.   I've already got a new sheet of .063 3003 aluminum for those parts, which should be even better to weld with oxy/hydrogen.  Makes me very enthusiastic to do the tank, new seat  & fender and do it even better than this RD350 seat.

[Canuck750]

Nice work Clint!   

[cliffrod]

Thanks, Jim.  I'm pretty stoked with how this looks.  I don't really do bucket list stuff- lf I want to do it, I generally just do it.  But this metal work & bikes is something I've been working towards for years.  It's great to finally turn the corner and be doing it.

It looks even better after a quick few licks with the file.  Think I can bump up the low spots and it will smooth up very nicely.  The goal now is to get some work done on the tank for my bike.  I would like to take it to a show in 2-3 wks and have more aluminum on it.


Edit- seat progress































 

[Rick4003]

Hi Cliffrod,

Really nice work with the seat! Thank you for posting!

I will be looking forward to follow the build on the Guzzi parts as well!

[cliffrod]

clint you better quit window shopping and go beat some metal if you hope to have a tank on the Corsa Record bike in time for The Meltdown! 

Hi Cliffrod,

Really nice work with the seat! Thank you for posting!

I will be looking forward to follow the build on the Guzzi parts as well!

Here you go, guys-

Today I started the tank for my bike.  I've studied a lot of other builds in recent years.  Many times the tank is either just made with no deliberate plan beyond an approx shape.  Others build a buck, but often find challenges with balancing sides, having a good centerline, produce no pattern for the tunnel and have mounting & handling issues with the buck during use.  I decided to build a modular buck to resolve many of the normal problems.  It is working very well.

Because I built dados to locate the stations using a strip of plywood ripped against the fence of a table saw, it was simple to assemble a similarly constructed mount to clamp into my vise.  I attached four pieces of that ripped dado spacer plywood to a piece of 2x6 and had a quick durable mount.









This mount allows me to move the buck to different positions if needed while working. 


With buck on working mount in vise, I made a paper pattern for the top center portion of the tank.  This was used to cut out the .063 thick 3003 aluminum blank from the full sheet, which was then trimmed close to the pattern after this pic.





Shaping began, using both arbor press and a teardrop pecan mallet that I recently turned & my old shot bag.  The RD350 seat proved to be a very productive exercise in some unexpected ways.  I canstill swing a hammer very well but have learned that I shouldn't.  The injury & recovery after a couple of vigorous sessions was pronounced after decades of stone work, where hammer work is more like a slow-paced marathon than the 100yd dash activity of Metalshaping.  The arbor press helps things hurt much less.

I worked the front and rear returns shaped into the initial form, as well as the small z-bend drop in the top.  I only had a couple of hours to work. 









Fit to buck is reasonably good for now.  Glad to be started. 

Edit- spent a little time in shop this morning.  Front return is smoothed up some & fitting better and the rear return is starting to lay back down where it needs to be.  The blank is a little wide, which makes shrinking along the sides more difficult but allows the more heavily worked metal to be trimmed to make a nicer part.









Once again, my goal on this bike isn't to make a perfectly smooth sanitized parts that are polished to perfection for the glitz factor.  That's now how the original Record bikes (or most race bikes & cars before the multi-million $$ contract and sponsorship days)  were built.  I want a bike that's more authentic to the original bikes, not overdone.

[cliffrod]

After another hour of blocking, shrinking wrinkles and wheeling it smooth, it fits pretty good.  It isn't absolutely lay flat on the buck like it could be, but it doesn't have to be to make me happy.  The shape is very good, very even and I like it.  There can still be a little more trimming when the sides are being fitted and that will help me improve & coordinate the fit.









Hopefully this weekend I can pattern and shape the sides.  They should go quickly.  I think the tunnel will, too.

[Canuck750]

That tank panel is looking real good, it sure looks to be a lot work and patience to form the aluminum let alone weld it up

[cliffrod]

Thanks, Jim.  It's a lot different doing aluminum than stone.  Super fast and forgiving, but I'm still learning.  Some things are a lot more challenging to achieve.

Made the sides this afternoon. 

























 The second side was quicker and easier to approximately fit to the buck.  The original bike tanks had a sharp line around the concave portion of each side. That's how I made the model and buck.  But when I started working these, I really like the jellymold shape as is and am now thinking about leaving it as is instead of adding that definition .   I've also got a little more return on the bottom edge of the sides right now.  I want to trim and fit these three pieces & tack them together, fold up the tunnel and see how it all looks on the bike. 

[Turin]

Very nice.

[cliffrod]

Thanks, Turin. I like these sides but have decided to make another pair that are more like the original tank and buck.  So this morning I cut out another pair of blanks and did the same for the tunnel.

First I had to make a pattern for the tunnel from the buck.  since the buck is made in two identical halves, marking a perfect centerline on the pattern to guide the bending/forming of the tunnel is simple.   Necessary clearance related to the tunnel & rest of the bike is also part of the buck, so that information could be transferred onto the pattern as well.
















image upload


Then I cut out blanks for the parts and trimmed them to an approx 1/4" margin with my Beverly Shear.   I marked the centerline and folds, got the cheap piece-o-crap-but-100%-FREE (guzzi content) harbor freight long brake off the wall and produced the two folds.  This brake is not very rugged, but fine for this project.  The clamp/shoe is just a piece of milled steel with a sharp edge.  To avoid damage to the metal, I covered the shoe's sharp edges with some duct tape.  No damage.





After that, I used the paper pattern to mark the location of the needed clearances on the blank.  These areas along the bend will basically be inverted.




 
I did some measurements and added a little to what seemed necessary to make sure it would be adequate.  Then I used the dimensions to make a pair of small wooden stakes, one concave and one convex, to aid in forming this concave detail.   Very cheap and easy-





The blank was held over the vise-mounted concave stake, the detail was developed & then planished a little with hammers and mallets using both stakes.  Because this stretched the metal some, the fold flattened out some and extra length in the metal made things a little wavy.  I used the English Wheel to help work the effective fold back to 90 degrees.  This one isn't perfect.  I used a steel hammer that was a little too heavy and it marked up the metal more than I wanted to.  But it will be out of sight & fine for this project.  And there's no reason to make it perfect yet unless the other side turns out significantly better.









Time to head back down to the shop and see how much nicer I can make the other clearance before bending it into the actual tunnel...

[cliffrod]

The second relief formed easier. I didn't use any steel hammers, so it didn't stretch & deform the metal in the same way.  No real planishing yet.  The folded flanges were squared up while I had it in the English wheel.  Bending the tunnel was done slowly to produce an even tunnel and overcome spring back or a sharp peak on the  centerline.  The black rubber mounting collars I made work great.  At this point the tunnel is still too long, but it still fits on the bike.  There's ok clearance for distributor but I still may relieve the bottom a little more to make sure.  Looking at old pics, this seems to be a good match for the placement of bottom of the original tanks.













the top was marked and conservatively trimmed to fit over the frame and approximately match the tunnel. Then the tunnel was trimmed on the ends as well so I could set all together on the bike.  Pretty happy.  The top will be trimmed a little more to drop the tank top profile lower on the bike, probably more at the rear than at the front.  The bottom flanges are still very wide near the valve covers, too.   I'll work the sides into shape first so all can be matched and trimmed together.

[Canuck750]

Nice CAD work Clint (cardboard assisted design)!

[cliffrod]

Nice CAD work Clint (cardboard assisted design)!

 

Nope- it's what my grandmother would call Clinton Arthur Design....  She always reversed my name.   Thanks, Jim.

I did the new sides today.  Started with two blanks and developed them in synch with each other.  I learned this as a chef and then during my stone apprenticeship.  Do the same thing to everything first, then step two, then step three... It usually produces more equitable results in less time.

All work was done with a couple of pecan mallets, shot bag, a couple of wooden (pecan) stakes in the vise and my English Wheel.

























Once they were mostly resolved, I tried them on the bike with top and tunnel












 
I knew the blanks had extra material at the bottom.  But they still looked wonky big.  When I got ready to mark then to cut them, I found the lower detail line was too low. If I cut the bottom off as is, the cut would be along this detail line.  Not cool.

But this is why I think this metal shaping work is such a great method & media.  I just moved the detail line. Marked it where it needed to be with a sharpie magic marker, put a different stake in the vise, grabbed a mallet and moved the line.  Then I cleaned up everything in the English Wheel.   Very cool.  By comparison, if this was a piece of granite, it would be thrown away and started over.  I've never had to do that, but know others who have.   

The mallet and sharp edge stake, both are pecan from my firewood pile-




there but for the grace of god lyrics


In process, moving the line approx 1 1/2" -









One side done, next to the other one still in the initial configuration for comparison-





After they were done, I marked the bottom for a close preliminary trim.  They look lots better on the bike now.  With the return at the bottom, engine access & clearance around valve covers, distributor and carbs is even better.  Looking from top, it's clear how much will be trimmed from the tunnel flange.

















Time to start the serious fine tuning for final fit & trim work so I can start tacking the top together.   

[cliffrod]

Tweaked the shapes of the sides a little yesterday, then started trimming and fitting the first side to the center today.  Get a pretty good fit but to the buck and to each other.  It also reduced the tank in size and achieved a better flow.  This tank is now narrower than my V7 Sport tank.





I had only planned to tack these together, but went ahead and welded it while the heat was in it.  Oxy/Hydrogen rig.  No flux on this 3003 aluminum base metal, just on rod.   It welds a lot easier and prettier than the 5000 series aluminum used for the RD350 cafe seat, but it still is a heat sink issue with the cooler oxy/hyd flame temps.  The outer 2/3 of the weld bead went ok.  The center 1/3 was really cold.  So I've still got more work to do.

No matter, it's looking good for now. 











 

Now I can trim, fit and spot weld/weld the other side in place.  The top still needs to be fitted to the tunnel, which should shorten the installed height.

[Turin]

Damn this is cool !

[twodogs]

Cool and very nice work 
Bruce

[cliffrod]

Thanks, guys.  the second side was trimmed and welded in today.  I had more success welding this side (more pre-heat, wrapped tank in blanket and used a bigger tip) but still  not complete success.  I dressed the welds with a file and will fix the flaws later.  Still lots more to do.  These pics aren't much different  but most are better quality than yesterday.  Last one is washed from the sunlight when I went outside to get a better angle.

Sure makes a nice pair of bikes to have side by side in the shop.





















Before I do any more fitting & trimming, it's time to work on the filler neck, vent and petcock bungs.