Approximate cost of Tank Tumbling?

[PR_SMITH]

I like that! I have one of those tank-caps available. I don't have access to a welder (or welder-skills) unfortunately. Though I have been thinking lately, it might be useful to take a metal-working class at some point.

As an alternative to welding the end, simply cut a slot in the end of the SS rod, either with a cutting wheel in a grinder, or use a hacksaw. Then center the cable in the slot, and bang the slot closed with a hammer.

 

[SlugLife]

As an alternative to welding the end, simply cut a slot in the end of the SS rod, either with a cutting wheel in a grinder, or use a hacksaw. Then center the cable in the slot, and bang the slot closed with a hammer.

I like that idea. The steel rod just arrived in the mail, and I managed to cut about 1.25 inches before my Dremel got very hot. The steel cable is supposed to arrive later today. Once I have the cable I'll see if I need to cut any more or not. (this is a 0.25 in x 36 inch rod if anyone is following along). I'll probably also grind some flat-spots along the top edge, to give the drill better grip.

I doubt anyone should need a rod any thicker, unless you go with another material like aluminum. or a wooden dowel. A longer rod would also be fine, I just wanted this to be a little easier to store.


edit: I ground the other end into a "hex" (6-sided) shape. It doesn't have to be "perfect" just good enough for the drill to grip onto.

 

[PR_SMITH]

I like that idea. The steel rod just arrived in the mail, and I managed to cut about 1.25 inches before my Dremel got very hot. The steel cable is supposed to arrive later today. Once I have the cable I'll see if I need to cut any more or not. (this is a 0.25 in x 36 inch rod if anyone is following along). I'll probably also grind some flat-spots along the top edge, to give the drill better grip.

I doubt anyone should need a rod any thicker, unless you go with another material like aluminum. or a wooden dowel. A longer rod would also be fine, I just wanted this to be a little easier to store.

View attachment 801570
edit: I ground the other end into a "hex" (6-sided) shape. It doesn't have to be "perfect" just good enough for the drill to grip onto.
View attachment 801590

If you find the slot in the 1/4" rod doesn't hammer down over the cable well enough, the a bit of epoxy should work.

 

[-JD-]

If you find the slot in the 1/4" rod doesn't hammer down over the cable well enough, the a bit of epoxy should work.

Wrapping the slit end with some the the cable, or even good braided line, and then epoxy would also help.

 

[Gone for diving]

I suppose the one thing I can't tell, is if the PVC it's 3/4-14 based on the description (they all just say 3/4). I might drag one of my empty 6cu bottles to a hardware store to be sure.

3/4 SPT is the most common in dive tanks. (Sometimes referred to mechanical straight pipe)

Same a 3/4 npt, just doesn't have a taper to the theads,

Note 3/4 npt etc measures closer to 1inch

 

[SlugLife]

How long do you think I should make the stainless-steel strands? I could do 7.5 to 8 inches (tank is 7in about), slightly larger than the tank diameter. Or a few inches more, to have the sides of the cable scrape along the inside.

 

[Boarderguy]

How long do you think I should make the stainless-steel strands? I could do 7.5 to 8 inches (tank is 7in about), slightly larger than the tank diameter. Or a few inches more, to have the sides of the cable scrape along the inside.

Think weed eater string... they will flex a bit while being spun around at drill speed.

 

[SlugLife]

I'll do a proper DIY writeup later, but here's what I have so far (pics below)

A few quick notes:

• I think 12-inches (6-inch radius) is about right for the strands.
• To secure the strands, a hammer didn't work. However, a table-vice-grip worked just fine. I also put a little bit of super-glue in the middle, which may or may-not be doing anything.
• I suspect fewer strands might be better. Fewer strands would be a little more flexible, and be easier to insert and remove in the tank-neck.
• To get the bottom of the tank, I pointed a couple strands downward using aluminum crimps that commonly ship with stainless-steel wire.
• 36-inch steel rod is honestly too long, it wobbles a little (but that's probably because I slightly bent it). I'll probably cut it closer to 24-inches.
• (not recommended) I didn't use the PVC thread protector yet. I got impatient and wanted to try it. So, I use some masking tape, and some pex pipe I had sitting around to protect the threads. I'm going to do it properly later, but I wanted to give it a quick try.
• I think it worked. It's currently hard to see through a fine cloud of rust in the tank, and I haven't washed out the tank yet, so the rust dust will be evenly distributed along the sides. I could blow it out but didn't feel like setting that up just yet.
• I'm thinking I may just take these tanks to hydro (8 months left, but I have 4 other thanks that need hydro, and might as well save a trip), and then do another whip (if needed) and wash then with water and a rust inhibitor and dry as quickly as possible.

 

[SlugLife]

I ended up buying one of these at a local hardware store in the middle of nowhere, with tax, it was $1.72. It threads perfectly, has a nice sized opening for inserting the whip, and covers 8-9 threads, which is plenty for steel.

 

[OMyMyOHellYes]

You are going to end up being a tank geek if you don't watch it, mister.