New 250 Project Adventure

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Snakeoil
Posts: 109
Joined: Fri Jun 17, 2016 12:10 pm
Location: Upstate NY

Re: New 250 Project Adventure

Postby Snakeoil » Sat Dec 10, 2016 10:46 pm

Just sticking these links in here since are part of the cam discussion for this project.


Cam nut removal
viewtopic.php?f=3&t=2401&start=10

Cam availability and measuring to ID
viewtopic.php?f=3&t=2408

Snakeoil
Posts: 109
Joined: Fri Jun 17, 2016 12:10 pm
Location: Upstate NY

Re: New 250 Project Adventure

Postby Snakeoil » Mon Dec 19, 2016 1:15 am

Internal tank prep

I have a 350 tank I want to use on the bike. The top inside surface and the top of the tunnel was pretty rusty. I tried Evaporust, but I apparently did not de-scale it well and the process simply converted the rust scale to Iron Phosphate scale.

So, I decided to build a shaker table to see if I could clean the tank with sand or some other abrasive in a similar fashion to a vibro-tumbler used to clean empty brass prior to reloading.

I only had mason's sand so that is what is in the tank now as I type this.

The table is simple. Piece of plywood with an old air furnace fan motor mounted vertically. There is an eccetric weight on the motor shaft to create the vibes. Table is hung from the rafters in my basement with 4 ropes. I have a fan blowing on the motor since there is no fan on the shaft itself and the motor was getting hot without good air circulation.

I just checked the tank after about an hour or so on the table. I also have a small container with a rusty washer and the same sand in it as a base-line check. The washer is looking better and the inside of the tank top section appears to have much less scale.

I'm going to leave it run for a few more hours before I turn in for the night. Tomorrow, I might go get a bucket of stone dust, small river stone and even small crushed stone to see if the process progress improves. I cannot read the dataplate on the motor. I suspect it is only an 1100 or 1800 rpm motor. A 3600 rpm motor would probably be better. We'll see.

Here is the tank on the table. Very high tech set-up.
Image

regards,
Rob

ecurbruce
Posts: 299
Joined: Fri Apr 01, 2011 12:43 am
Location: Lakeland fl

Re: New 250 Project Adventure

Postby ecurbruce » Mon Dec 19, 2016 6:12 pm

Hey Rob,
I'm liking the creativity of your shaker table...
Are you doing that sand wet, or dry?
I did my tank similarly with around a gallon of small bolts and nuts and washers and etc. In water. It worked well, removed scale, but not quite to Shiney metal. Plenty clean, though.

Bruce

Snakeoil
Posts: 109
Joined: Fri Jun 17, 2016 12:10 pm
Location: Upstate NY

Re: New 250 Project Adventure

Postby Snakeoil » Mon Dec 19, 2016 10:36 pm

Sand is dry, Bruce. Dry means no flash rust. If I were to do it wet, I'd use something like mineral spirits.

Well, this set up sorta worked. The basic problem is the sympathetic action the abrasive takes in response to the rotating eccentric makes the media tend to head to the same spot. I noticed this with sand in my clear plastic test contain that had running on the same table with the tank.

Today, I put No. 1 river rock, which is the small pebbles you find in streams, in the tank and turned it on. The rock moved more than the sand, but that also meant it tended to go to one side as well. I was interesting to watch. I left the cap off the tank and fill it about 1/3 full of stones, so there were stones on each side of the tunnel. I turned on the motor and watched the stones merrily dance down the right side of the tank to the rear, cross over the tunnel and proceed back up the left side where they started to pile up in the left front of the tank. I let it run and to my amazement, the last few stones on the right managed to actually jump over the tunnel at the rear and follow the others, like lemmings.

I flipped the motor 90 degrees to change the direction of the vibrational movement. This resulted in one side of the tank vibrating the stones like made while the other side barely did anything.

So, I've taking the motor off and put it back on the shelf to gather dust. I'm leaving the table suspended as is and will use it as a manual shaker table. In the past I've always done the cha-cha with a tank filed with sheetrock screws or before that, nuts and bolts. Now I'll use the stones. It means rotating the tank 90 degrees for each turn at scrubbing.

I thought about making a true tumbler, similar to putting the tank in a cement mixer. But it would take too much room. My neighbor had a cement mixer. Could've bought it when he died. But did not want to store it. Gotta poke my friends. I'm sure one of them has one.

The sand did a pretty good job. But there were a few spots where I could still feel some scale. I got one piece to pop off with a fingernail. But needless to say, I cannot reach very far into the tank. But a mirror and light indicates it's pretty good inside now. I think a trip thru the manual shaker table tomorrow should do the trick. Might toss in my small bucket of sheet rock screws. Those things are like tiny little files.

regards,
Rob

Snakeoil
Posts: 109
Joined: Fri Jun 17, 2016 12:10 pm
Location: Upstate NY

Re: New 250 Project Adventure

Postby Snakeoil » Tue Dec 20, 2016 6:17 pm

As a follow up to the previous post, yesterday I filled the tank about 1/3 full of the river stone and used the shaker table in manual mode, meaning rowing it back and forth by hand. I did each of the 4 sides and it worked very well. All scale was cleaned out of the tank. I'm happy with the results.

Time to start pulling the dents.

Merry Christmas,
Rob

DBDBrian
Posts: 197
Joined: Mon Mar 30, 2015 11:29 pm

Re: New 250 Project Adventure

Postby DBDBrian » Tue Dec 20, 2016 9:26 pm

Ingenious set up Rob, a pity you had to revert too manual operation. I tried the Maraca type shake by hand, but soon gave up on that one. My thoughts then turned to the cement mixer, I knocked up a couple of brackets and bolted it to the bowl.
I used about two pints of pea shingle, mixed with diesel, rocking the bowl back and forth while it was rotating. A good result was obtained in quite a short time, it would have been benefical if the rotation could have been reversed for a time, to cascade the shingle the opposite direction.

Brian
P1040129.JPG
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Brian
Made in England

Snakeoil
Posts: 109
Joined: Fri Jun 17, 2016 12:10 pm
Location: Upstate NY

Re: New 250 Project Adventure

Postby Snakeoil » Wed Dec 21, 2016 12:12 am

Thanks Brian. Another reason I did this dry, was in case it turns out I need to line the tank. I'd prefer not to have to degrease the interior.

Pulled the dents today. Used my trusty "Dent-B-Gone" which was another hair-brained invention I came up with, only to find out they have been using this type of tool and my process for sometime now. The tool is a Horror Fright slide hammer and some pulling tools made by welding a washer to the end of a bolt and drilling holes in the washer. The dent puller is afixed to the dent with hot glue. The holes in the washer help it get a better grip. The glue tend to let go as the dent is pulled out to its original shape. I've pulled quite a few tank dents with this tool over the years on vintage as well as modern tanks and have yet to over-pull a dent.

Here are before and after shots for the dents in the tank. I know I mentioned this before, but this tank is supposedly off a 350 single. But it looks just like a Diana tank to me. Maybe they are identical.

RIGHT SIDE

BEFORE
Image
Image

AFTER
Image
Image

LEFT SIDE

BEFORE
Image
Image

AFTER
Image
Image

TOP

BEFORE
Image

AFTER
Image

FRONT LEFT TOP

BEFORE
Image

AFTER
Image

The last dent, the Front left top, was very sharp and deep. Pulling it with the tool was fruitless because it would have required a small tool and such a tool will not get a sufficient grip to do any good. So, I got a good deal of it out with heat shrinking using a propane torch. I might braze a stud to it and pull it the rest of the way out. Probably not worth it.

The dark areas in the "after" pics are where the tank was apparently struck by whatever caused the dent. They are small, shallow, and sharp recesses and not worth trying to get out. If I could get on both sides with a body hammer and a dolly, I could make them disappear. Someday, I'd like to make a set of tank hammers, but it's is very low on the priority list. If I did this all the time, I would have them by now.

I'm happy with the result. Need to strip the remaining paint off, do the necessary filling and take to my painter to prime. Have not decided on a color or paint pattern yet.

regards,
Rob

Rick
Posts: 340
Joined: Thu Nov 11, 2010 1:12 am
Location: Northern Plains, USA

Re: New 250 Project Adventure

Postby Rick » Wed Dec 21, 2016 3:37 pm

Rob-
A local guy who cleans tanks as part of his business has a rig similar to the cement mixer, but uses sheetrock screws instead of sand or rock- he told me he experimented and found the sharp ends and threads of the screws did the best job of cleaning a tank.
I have some tanks with shallow dents- I've seen the hot glue setups but always thought they'd only work on paper thin auto bodies- I'll give it a try.
Rick

Snakeoil
Posts: 109
Joined: Fri Jun 17, 2016 12:10 pm
Location: Upstate NY

Re: New 250 Project Adventure

Postby Snakeoil » Wed Dec 21, 2016 4:47 pm

For grins I did a search on "auto body hot glue" to see if they made a hot glue with more bite for this kind of work. I found this and thought it was pretty interesting. It is bascially what I made for myself, only it uses a much smaller slide hammer.

https://www.vidaxl.com/p/210299/32-piec ... oCmuzw_wcB

I found several of hte PDR tool websites and they all sell various grades of glue. Ebay of course has it as well. Spoke to my local autobody supply shop and they have one grade that costs $40/ten sticks. Called a local Michael's Craft store and they only have hot glues that come in different temperature ranges. I assume this if for using it where it might be in the hot sun so it melts at a higher temp.

Going to check local places like Home Depot for their glues and see if they sell a high strength version.

I did get some good ideas for making new dent pulling tools. I might be able to pull that sharp dent with the right tool. Have all winter to get it out.

One thing I found out about the dent specific hot glue is some do not need a solvent to remove and others use alcohol, which normally will not hurt paint. Never tried alcohol to get the glue off. Always used acetone since I'm never trying to save the paint.

regards,
Rob

Snakeoil
Posts: 109
Joined: Fri Jun 17, 2016 12:10 pm
Location: Upstate NY

Re: New 250 Project Adventure

Postby Snakeoil » Sat Dec 31, 2016 9:39 pm

Took the tank over to my buddy's Jake's shop and blasted all the paint off. My blast cabinet was just too cramped to do the tank. Thought I noticed a leak by on petcock bung during the blasting process. I had remnant of min spirits in the tank and it looked like they were leaching out.

I had noticed copious amounts of solder around both bungs. I was doubtful this was factory workmanship. So the potential leak looked like a crack at the base of the small depression/cupped area for the bung. I hit it with a torch and blow off the excess solder. Yup, what looked like a crack extended under that glob of solder.

I pressure tested the tank and have to say this is the tightest crack I've ever found in a tank. I have found cracks too small or tight to find with the human eye without magnification. But they always made bubbles when pressure tested. Not this one. It is so tight that I had to put quite a bit of pressure in the tank before it started to bubble the soapy water.

Attached a pic below. Crack starts at the end of the dental probe and goes to the right.

I have to decide how I'm going to fix this. I know I should drill stop holes on each end. Then I'm thinking of brazing it, which means I need to grind it out to remove any errant solder in the crack. Glad I found it before I painted the tank. What is interesting is it did not appear to have compromised the old paint. Could be the paint was enough to seal it up.

Never a dull moment.

Rob
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