YotaTech Forums  

Go Back   YotaTech Forums > Off Road Tech, Fab Shop, Solid Axle Swaps, Tool Time, & Engine Swaps > The Fab Shop
Sign in using an external account
Register Forgot Password?
Search


The Fab Shop Tube buggies, armor protection and anything else that requires cutting, welding, or custom fab work

Welcome to Yotatech!
Welcome to Yotatech,

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, at no cost, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!


Reply
 
LinkBack Thread Tools Search this Thread
Old 04-12-2005, 01:03 PM   #1
Contributing Member
Personal Sales Rating: (0)
 
getitdone's Avatar
 
Join Date: Jul 2004
Location: Ft. Collins, Co
Posts: 987
Make your own air tank?

I was wondering just how hard would it be to weld up a box and use it as an air tank?
There is a nice pocket of space in the fender behind the cardboard walls in the interior. I was thinking of building a box that would take up all that space efficently and using it for air storage. Any thoughts?
This ad is not displayed to registered members.
Register your free account today and become a member on Yotatech!
__________________
Chris Fischer


3D 85 4Runner SR5 | 33" BFG M/T on flat black rims | Chevy springs | Custom Grab cage with overhead cb mount | Custom fabbed center console | Freshly rebuilt axle with IFS hub/caliper swap | Rock Sliders | Lots more...


In Colorado, Dig.
getitdone is offline   Reply With Quote
Old 04-12-2005, 01:08 PM   #2
Banned
Vendor Sales Rating: (0)
 
jimbo74's Avatar
 
Join Date: Jan 2004
Location: Nor*Cal
Posts: 6,590
Send a message via AIM to jimbo74
yuo could do it, but will need a drain at the bottom and also a need to severly coat the inside to resist rust... also your welds would basically have to be perfect......
jimbo74 is offline   Reply With Quote
Old 04-12-2005, 04:31 PM   #3
Contributing Member
Personal Sales Rating: (0)
 
Robinhood150's Avatar
 
Join Date: May 2002
Location: Wandering around Phoenix
Posts: 6,033
Send a message via AIM to Robinhood150
There's a reason most air tanks are round. Try blowing up a paper sack, what shape does it try to become? Round. That's what'll happen to a square tank unless it has seriously thick walls. You don't want to mess around with pressure vessals, plus air tanks are cheap to buy.
__________________
Steve. '93 4Runner V6 Auto 4x4
Robinhood's Lair. || Gettin' Off 4wd Club member

Lots for sale:5.29 ARB IFS third member... Click

Sierra Club policy: [A reason to close trails] ...Physical soil damage, often readily visible, resulting in:
a. Erosion, causing soil loss and damage to stream banks, streams, and fish habitat...
Lesson...Stay on the TRAIL!
Robinhood150 is offline   Reply With Quote
Old 04-12-2005, 04:34 PM   #4
Banned
Vendor Sales Rating: (0)
 
jimbo74's Avatar
 
Join Date: Jan 2004
Location: Nor*Cal
Posts: 6,590
Send a message via AIM to jimbo74
ah, good point, didnt even think of that.... even custom bumpers that hold air have round tubes.....
jimbo74 is offline   Reply With Quote
Old 04-12-2005, 04:43 PM   #5
Registered User
Personal Sales Rating: (0)
 
crash's Avatar
 
Join Date: Jun 2002
Location: GOLDBAR BABY!!!
Posts: 910
My air tank is square, not coated inside and doesn't have a drain..

Guess I just don't follow anybodys rules
__________________

STUFF for SALE

crash is offline   Reply With Quote
Old 04-12-2005, 05:08 PM   #6
Contributing Member
Personal Sales Rating: (0)
 
Robinhood150's Avatar
 
Join Date: May 2002
Location: Wandering around Phoenix
Posts: 6,033
Send a message via AIM to Robinhood150
Yeah, but how thick is the steel? Much thicker than a store bought round one, I bet.

I mean, yeah, lots of people use square sliders or bumpers for air tanks, but they're using 3/16 to 1/4 tubing and usually it's 2x2 stuff. One wall of a 10"x10"x10" cube has an area of 100". At 100psi that's 10000 lbs of force exerted on 1 wall. Plus, you have to take into consideration fatigue and corrosion.
__________________
Steve. '93 4Runner V6 Auto 4x4
Robinhood's Lair. || Gettin' Off 4wd Club member

Lots for sale:5.29 ARB IFS third member... Click

Sierra Club policy: [A reason to close trails] ...Physical soil damage, often readily visible, resulting in:
a. Erosion, causing soil loss and damage to stream banks, streams, and fish habitat...
Lesson...Stay on the TRAIL!

Last edited by Robinhood150; 04-12-2005 at 05:13 PM.
Robinhood150 is offline   Reply With Quote
Old 10-15-2007, 02:38 PM   #7
Contributing Member
Personal Sales Rating: (0)
 
glenyoshida's Avatar
 
Join Date: Aug 2006
Location: Denver, CO
Posts: 266
Hi Chris,

I'm breathing life back into an ancient thread. I've heard a lot of talk about making custom tanks but no one that I know of has done it.

I also thought this would be a cool thing. I think I have a basic understanding of how to design a tank but please (anyone) post up and let me know if I made any errors. From what I read there is a real danger of serious injury or fatal explosion with air tanks as large as what we might need to fill four 33" tires. I'd rather be wrong than maimed or dead.


Around 1.5 cu ft tank (about 10 gallons) or so is needed to air up four 33" tires at 130 psi.

Basically the bigger the tank the thicker the walls need to be? A tank that would fit under the rear where the spare tire normally lives could be as big as 9" x 12" x 36" that's about 2.25 cu ft or 3888 cu in. This is making a rectangular tank that does not have to go around the vapor system in the spare tire area that was new to the 2001 and 2002 4Runner models.


To make it easy to figure out the wall thickness I converted the equivalent volume to a cylinder form equaling a vessel 36 inches long with a radius of 10.5 inches.

The below formula calculates the wall stress for the cylindrical section, the stress in the hoop direction (in a circle around the wall).


t = (p x r) / sigma

Where:
p = pressure in psi
r = radius of the cylinder
t = thickness of a wall
Sigma = the tensile strength of the material

Mild steel has a tensile strength of about 55,000psi
Stainless 304 has a tensile strength of about 80,000psi

This figures out the the bursting thickness. So we should at least quadruple (4x) the margin of

safety.

Plug in the numbers using stainless steel and you get:

t = (130psi x 10.5) / 80000
t = 0.017 inches thick x 4
A safe thickness is 0.068"


That makes the wall thickness 1/16" thick (0.0625" = 1/16th inch) thick if we made it out of stainless 304 if it's mild steel then it would need to be 0.099" or 3/32" inches thick.

I'm assuming stainless steel is the way to go instead of mild steel because of the problem with condensation forming in the tank and rusting the tank from the inside out until it potentially explodes.

To help with ideas for other tank sizes keep in mind the larger the tank the thicker the walls need to be?

For example:

A 10" cube tank filled to 130 psi will have 13000pounds of push on each tank wall.
A 1" cube at 130 psi would have 130 pounds on each inch of the tank wall.

BTW the formula to figure the pressure at the ends (the AXIAL pressure) is:

t = (p x r) /2 x Sigma

Can anybody verify my calcs? 1/16th inch stainless 304 seems pretty thin for a tank even if the

problem of preventing the sides from deforming is figured out.
__________________
- Glen -
2001 4Runner Auto - Armorology Bumper - Stainless rear bumper - Warn M8000 w/Wireless remote, 1/2" Technora line - Toytec coilovers - OME 851s w/Bilstein 5100s - Yokohama Geolander MT+ 305/70R16 - Stubbs HD-SKO Sliders - Engel 15 Freezer - Toytec Rear LCA skids - Budbuilt front & belly - Low profile cargo -Viper 5900 remote start - Cobra 18WSXTII CB - VSC disable switch - 2nd Battery - inverter - Interior CO2 ports - Nitro 4.88s - ARB Air Lockers F&R Photos

Last edited by glenyoshida; 06-18-2009 at 10:07 AM.
glenyoshida is offline   Reply With Quote
Old 10-15-2007, 02:38 PM
Yotatech
4WD Truck




Paid Advertisement
Reply

Tags
air, bottle, build, create, make, oxygen, psi, round, rounded, square, tank, tanks, thick, thickness, wall

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
What size air tank? Albuquerque Jim 95.5-2004 Tacomas & 96-2002 4Runners 3 08-24-2005 09:22 PM
Air Tank? nees1212 95.5-2004 Tacomas & 96-2002 4Runners 1 07-13-2004 12:45 PM
Air tank possibility? Tacoma Dude Offroad Tech 25 06-01-2004 04:41 PM
Air tank for on board air mtnbkr Offroad Tech 2 05-05-2004 06:42 PM
7 Gallon Air Tank jimrockford 95.5-2004 Tacomas & 96-2002 4Runners 11 12-09-2003 07:57 PM


All times are GMT -8. The time now is 02:35 PM.


2010 InternetBrands, Inc.