No bed built?

[Pete Kildow]

I know most use the bed as extra weight on the rear-end. So by going single axle without the bed. Was thinking about building 2 boxes. Fill these with 1500# of lead, use one on each side of the hitch.  This way I have the ballast back there for bob-tailing. I have around 47000 to 48000 of soft lead on hand. So would not be an issue to use 3000 lbs of it on the truck. Right now its in big slabs, 2.5" thick and 50" wide x 66" long. Some are encased in 1/4" Steel, while the rest are encased in 3/8" SS. These were ballast weights off indoor cranes at a ship yard.

I bought them for the lead. We have a Spin Cast setup. That cranks out fishing sinkers, Jigs and stuff by the Thousands per day. Never did get the stuff set up and running. So have the lead just sitting here. So thought why not use some of it on what ever truck we go with.

Fit a box between the frame rails at the rearend. 18"x6"x24" that's a little over 3000 lbs plus the box weight. This could be build where it sits on the frame rails and bolted to the rails also. Plus behind behind the axle and under the hitch. That should add the weigh to the rear axle. But would not want to to take away from the steer axle weight?

Just thinking out loud here, but if it would be better to add the weight right behind the sleeper. Just build a box SQ and mount to the frame rails right behind the sleeper? 14" SQ x 40" long bolted to the top of the frame rails. That and the box should be around 3300 lbs. Could pour the lead in 3 or 4 pieces. Take the loader and sit them into the box Would not be hard to build. And not have much in the box. And guess I would just make a bigger box. Then play with the weights until I fine tune the ride and axle weights.

Any pointers on doing this please add them.

Pete

[Scrap]

Don't go to California, or visit Flint, MI!  LOL  The more the better since you don't have ABS, plus it takes a lot more to change the weights on the front of a set forward truck than a set back.  Don't put near the sleeper suspension xmember area as that is a 'weak' spot if not spec'd for it.  It is also a spot that can cause beaming and give you front end bounce.  And watch your rail RBM if you hang it behind axle.  There's been some hitch talk here that put RBM well over half, then hang some counterweight and it could put it over.  You are probably somewhere around 1.7-2.1M RBM so calculate your setup, then put in a factor of safety for rusted rails.  Best place is probably near the fwd suspension xmember?

So your spin cast setup for all that work must be the big industrial one with the spin pot that goes in the big washing machine looking tub?  Interesting stuff.  You need to give us a picture tour of it!

[Pete Kildow]

5 hours ago, Scrap said:

Don't go to California, or visit Flint, MI!  LOL  The more the better since you don't have ABS, plus it takes a lot more to change the weights on the front of a set forward truck than a set back.  Don't put near the sleeper suspension xmember area as that is a 'weak' spot if not spec'd for it.  It is also a spot that can cause beaming and give you front end bounce.  And watch your rail RBM if you hang it behind axle.  There's been some hitch talk here that put RBM well over half, then hang some counterweight and it could put it over.  You are probably somewhere around 1.7-2.1M RBM so calculate your setup, then put in a factor of safety for rusted rails.  Best place is probably near the fwd suspension xmember?

So your spin cast setup for all that work must be the big industrial one with the spin pot that goes in the big washing machine looking tub?  Interesting stuff.  You need to give us a picture tour of it!

Thanks and yes the spin casting is the big tube like deal. Has air cylinder, that squeezes the molds shut. Pour in lead and 1 minute later you have anywhere from 50 small jigs to a 12 4 oz jigs. Melting furnace is propane and hold 160 lbs of lead at a time. Also have a 30,000 lb Vulcanizing press for making my own molds.

Also can be used to make small plaques out of pewter. Along with belt buckles.

[RandyA]

I haven't done this but I've been looking and thinkin'.  It may come to fruition yet.  Been looking at both Goodyear and Firestone air spring specs.   Anyway, I want to see what Scrap thinks.........  Replace the OEM truck rear air bags with a smaller diameter bag - remember PSI of air is not same as weight.  Got to have that pi-r-square thing in there to get weight - in this case both support and compressability.  Skinny air bag with same inflated height doesn't change drive line angle or hitch height.  Not the same as lowering air pressure on OEM bags.  Maintain OEM air pressure via leveling valve in skinny bags.  I still have the "Z" springs to contend with but a smaller diameter air bag with same height as OEM bags could translate to more suspension movement or softer ride - on paper anyway.  I've just never been able to wrap my brain around adding dead weight to fix the suspension.  You can't create or destroy energy - only convert it.  Unless you are going downhill added weight will burn more fuel.

[Pete Kildow]

Just a thought, but used on other app's. Ping tanks has made other air bags ride better. Being that ping tank give's the air more room to move. Have read where people with the 8 bag kW setup have used them. Also on air helper bags on pickup's. I know the ping tank makes a world of difference.

Pete

[rickeieio]

2 hours ago, RandyA said:

I haven't done this but I've been looking and thinkin'.  It may come to fruition yet.  Been looking at both Goodyear and Firestone air spring specs.   Anyway, I want to see what Scrap thinks.........  Replace the OEM truck rear air bags with a smaller diameter bag - remember PSI of air is not same as weight.  Got to have that pi-r-square thing in there to get weight - in this case both support and compressability.  Skinny air bag with same inflated height doesn't change drive line angle or hitch height.  Not the same as lowering air pressure on OEM bags.  Maintain OEM air pressure via leveling valve in skinny bags.  I still have the "Z" springs to contend with but a smaller diameter air bag with same height as OEM bags could translate to more suspension movement or softer ride - on paper anyway.  I've just never been able to wrap my brain around adding dead weight to fix the suspension.  You can't create or destroy energy - only convert it.  Unless you are going downhill added weight will burn more fuel.

Not to nit-pic, but you can also store energy, which is the lead in to the quote below...................  And I've been struggling with the idea of skinny bags too.  I think you're on to something, I just don't have the technical background to work it out.

1 hour ago, Pete Kildow said:

Just a thought, but used on other app's. Ping tanks has made other air bags ride better. Being that ping tank give's the air more room to move. Have read where people with the 8 bag kW setup have used them. Also on air helper bags on pickup's. I know the ping tank makes a world of difference.

Pete

Ping tanks might work well, on a KW, but I doubt it on a Volvo.  Reason being, the air lines are very small on a Volvo, 1/4" v. roughly 3/4" on a KW.  But I like the way this is headed.

I can see Randy rummaging around a truck recycling yard and emerging with a set of bags, an old air tank, and some tubing and creating a "kit."

[Jack Mayer]

I've put ping tanks on MDTs and they work well. But you have to replace the lines with larger diameter to get the air movement required. I'm not sure how they would work on an HDT, but I don't see a reason why they would not, if done properly. I'll leave it to Henry and Scrap to figure all that out....

[ALLOY]

On 7/2/2017 at 9:00 AM, Pete Kildow said:

I know most use the bed as extra weight on the rear-end. So by going single axle without the bed. Was thinking about building 2 boxes. Fill these with 1500# of lead, use one on each side of the hitch.  This way I have the ballast back there for bob-tailing. I have around 47000 to 48000 of soft lead on hand. So would not be an issue to use 3000 lbs of it on the truck. Right now its in big slabs, 2.5" thick and 50" wide x 66" long. Some are encased in 1/4" Steel, while the rest are encased in 3/8" SS. These were ballast weights off indoor cranes at a ship yard.

I bought them for the lead. We have a Spin Cast setup. That cranks out fishing sinkers, Jigs and stuff by the Thousands per day. Never did get the stuff set up and running. So have the lead just sitting here. So thought why not use some of it on what ever truck we go with.

Fit a box between the frame rails at the rearend. 18"x6"x24" that's a little over 3000 lbs plus the box weight. This could be build where it sits on the frame rails and bolted to the rails also. Plus behind behind the axle and under the hitch. That should add the weigh to the rear axle. But would not want to to take away from the steer axle weight?

Just thinking out loud here, but if it would be better to add the weight right behind the sleeper. Just build a box SQ and mount to the frame rails right behind the sleeper? 14" SQ x 40" long bolted to the top of the frame rails. That and the box should be around 3300 lbs. Could pour the lead in 3 or 4 pieces. Take the loader and sit them into the box Would not be hard to build. And not have much in the box. And guess I would just make a bigger box. Then play with the weights until I fine tune the ride and axle weights.

Any pointers on doing this please add them.

Pete

Steel frame with Alum boxes with alum extruded plank deck with lead melted into boxes as you describe.....no sandblasting....no need to paint the inside of the boxes/wheel wells.

Alum lends itself to shaping and finishing much better than steel does.

 

[Alie&Jim's Carrilite]

20 minutes ago, rickeieio said:

 

Ping tanks might work well, on a KW, but I doubt it on a Volvo.  Reason being, the air lines are very small on a Volvo, 1/4" v. roughly 3/4" on a KW.  But I like the way this is headed.

I 

 

Our rear bags are plumbed with 3/8 line.  It would be easy enough to swap fittings to 1/2 and run new line to the tank.... Problem is on our short wheelbase and bed, it's already crowded under the bed.  What volume of tank would be needed?

[rickeieio]

1 hour ago, Alie&Jim's Carrilite said:

Our rear bags are plumbed with 3/8 line.  It would be easy enough to swap fittings to 1/2 and run new line to the tank.... Problem is on our short wheelbase and bed, it's already crowded under the bed.  What volume of tank would be needed?

Huh?  I feel cheated.  Both my Volvo and Mack have little spaghetti lines.  Did Volvo fit different lines for different spec'd trucks?

[Alie&Jim's Carrilite]

2 hours ago, rickeieio said:

Huh?  I feel cheated.  Both my Volvo and Mack have little spaghetti lines.  Did Volvo fit different lines for different spec'd trucks?

Not cheated, just OLD sckool.... 1998 model when they used real parts.....LOL

[shorts]

Randy and Rick if you are serious about resizing your airbags and want or feel the need for more input an inquirey to application engineering just might get you connected to a real person that is in the know and deals with products specing them on a regular basis. Many years ago I was looking at building an air ride off road toy, the bag that I was looking to use was a very pricey industrial bumper, a conversation with app. engineering got me a better/longer travel air spring with a part number that was reasonably priced and not listed as a production part number.  I went to my local truck parts supplier and had them order my bags by part number and only had to wait a week or 10 days for delivery.

[rickeieio]

I would only be serious about swapping bags if it were cheap, and if ever there were a man who could figure out how to do it, I feel sure Randy is that guy.  His resourcefulness is amazing.

My trucks are 2000 (Mack CH613) and 2001 (Volvo 770). so yeah, \maybe they changed things later in production.

I'd like to use bigger lines on the Mack, as it would let the axles follow terrain better when pulling a load of grain out of the field.

[Alie&Jim's Carrilite]

 

Rick-  My bags have 1/2-npt threads on them, the splitter block as well.  They reduce to 3/8.  Might be worth a looksee to see what the fitting size is.  I had a transmission leak that had been repaired at one time with a creative assembly of 1/2 to 3/8 to 5/16 and back to 1/2.  I changed that upon finding it.  How big of a tank is needed to soften the ride?

[rickeieio]

I'd have to look to be sure, but I believe my bags use 1/4" npt. I may need to find an old bag to cut up and see if I can drill out the holes and re-tap.

[noteven]

Firestone Air Ride design guide

[Pete Kildow]

I know on the old AG100 8 bag air ride on Kw's. There's a big line kit for it. You swap out the bags for the bigger fittings and lines. And it from what I have been told. Makes the ride so much better on the KW's.

As for the size of the ping tank. From what I have been told. Along with reading up on them. Most use a 2.5 Gallon tank for 2 bags. But there's some that have used a gallon tank per bag. And claim there's no difference.

Pete

[Hot Rod]

Just curious, are you opposed to the idea of having a bed at all, or just the cost of a bed?  Because I looked the price of scrap lead, and it seems like if you sold off the lead you were going to use on this project, and add it the money your are going to spend on boxes and brackets and such, you'd have enough money or at least a good start on buying a big pile of nice new steel to build a bed.  I know myself and a lot of folks on here have built there own on a similar budget.

[RandyA]

OK.... I know Pete started this thread asking about adding weight to the truck bed to counteract the spring rate of the OEM air springs.  I hope this does not take the thread off the original intent as after all the bottom line is improving ride quality.  We can add weight to the suspension to try and equal design parameters or we can redesign the suspension so the added weight is not needed.

About ping tanks, accumulators, air hammers or what ever one wants to call them...... yes, they have the ability to improve spring rates for less pin weight on our trucks but we do have some problems to get around if they are to work on, for example, my 2004 Volvo.  Other trucks may be different - I don't know.  On my truck the supply lines to the top metal plates on the two air springs (I'm singled) are 3/8" OD and 1/4" ID.  The air springs are in parallel for each side of a tandem axle (left or right side together).  The threaded fitting on the top metal plate of each air spring is 1/4" NPT.  The size of the ping tank in cubic inches, feet or gallons is not as critical as the size of the air line between the air spring and the ping tank.  1/4" is just too darn small to pass air in any volume/speed that would effectively improve ride quality.  I'm thinking we need something like 1/2" between the air spring and ping tank.  Adapters to go from 1/4" to 1/2" are not going to work.  You can't have a restriction and expect to have the needed air flow in both volume and speed.

Hold that number for a minute....

The top plate on my air springs is steel.  That means it can be drilled and have a fitting brazed or welded on top or if the metal is thick enough (?) simply drilled and tapped (now I wish I had kept one of my old bags).  There is enough exposed steel to add a fitting by one of the above methods for a 1/2" line. 

Looking at what to use for a ping tank..... both steel and aluminum portable air tanks are readily available for decent prices.  But they do take up a lot of space due to their diameter.  .  Another "idea" that comes to mind is using schedule 40, or maybe even schedule 80, PVC pipe.  4" diameter by "x" length to get a specific volume comparable to at least 50% or more of the air spring.  If you have room maybe 6" PVC of a shorter length .  Solid end caps with one end having a 3/4" NPT threaded nipple.  The pressure ratings for schedule 40 PVC with the correct high strength glue are well within the max PSI of the suspension system, even when "pinging" (180 psi at 75 degrees F is nominal for schedule 40).  There are lots of places one could fit these PVC accumulators under the truck.    Another suggestion is to use  portable welding gas cylinders.  I have several outdated ones here that would be fine for low pressure air - in fact I used two of them to make an accumulator for my utility air supply line that are mounted on the back of my cab.  10 pound fire extinguisher cylinders should work as well - and if they are steel fittings can be brazed on.  It is not hard to find them.  There were at least a dozen out-of-date C02 extinguishers sitting out at our recycling center on my last visit (empty).  1 gallon expansion tanks normally sold for water, air or RO system storage are cheap and the ones with an internal air bladder could make for some interesting experiments in tuning a ping tank. 

Now, citing some basic physics principals related designing an air spring suspension: " The bigger the volume of the bag in height, not diameter, the better the ride because the air pressure increases with less progression during compression of the bag and offers less resistance and allows further travel of the suspension."    Well, we can't make the bags taller - that would screw up ride height.  A bigger bag in diameter would actually give a harsher ride (you have to think on that one).  But, an air bag with the same height as our current bags but of a smaller diameter would translate to a softer ride - as could a properly designed ping tank.  Which one to use?  Don't know.  If I could find a narrower bag for the $100 each I paid for the OEM ones I replaced when I singled I would be more inclined to go that route for the sake of simplicity.  You can change out air bags on a Volvo with a 2x4 wedge in the Z spring in 15 minutes or less.  Like I said, I'm thinkin' and figgurin' on it and if and when I come up with an answer I will surely let everyone know.  Oh, and Shorts, yes - definitely help from an application engineer on selecting the right bag.   Sizing is not linear.  Sprung and un-sprung weights have to be known. I've got to get the math right before I do anything.

 

[jeffw]

PVC for compressed air can be dangerous:

 

http://www.practicalmachinist.com/vb/general/ruptured-pvc-air-lines-what-not-do-230253/

[Dollytrolley]

On 7/2/2017 at 9:00 AM, Pete Kildow said:

I know most use the bed as extra weight on the rear-end. So by going single axle without the bed. Was thinking about building 2 boxes. Fill these with 1500# of lead, use one on each side of the hitch.  This way I have the ballast back there for bob-tailing. I have around 47000 to 48000 of soft lead on hand. So would not be an issue to use 3000 lbs of it on the truck. Right now its in big slabs, 2.5" thick and 50" wide x 66" long. Some are encased in 1/4" Steel, while the rest are encased in 3/8" SS. These were ballast weights off indoor cranes at a ship yard.

I bought them for the lead. We have a Spin Cast setup. That cranks out fishing sinkers, Jigs and stuff by the Thousands per day. Never did get the stuff set up and running. So have the lead just sitting here. So thought why not use some of it on what ever truck we go with.

Fit a box between the frame rails at the rearend. 18"x6"x24" that's a little over 3000 lbs plus the box weight. This could be build where it sits on the frame rails and bolted to the rails also. Plus behind behind the axle and under the hitch. That should add the weigh to the rear axle. But would not want to to take away from the steer axle weight?

Just thinking out loud here, but if it would be better to add the weight right behind the sleeper. Just build a box SQ and mount to the frame rails right behind the sleeper? 14" SQ x 40" long bolted to the top of the frame rails. That and the box should be around 3300 lbs. Could pour the lead in 3 or 4 pieces. Take the loader and sit them into the box Would not be hard to build. And not have much in the box. And guess I would just make a bigger box. Then play with the weights until I fine tune the ride and axle weights.

Any pointers on doing this please add them.

Pete

 

On 7/2/2017 at 10:45 AM, Scrap said:

Don't go to California, or visit Flint, MI!  LOL  The more the better since you don't have ABS, plus it takes a lot more to change the weights on the front of a set forward truck than a set back.  Don't put near the sleeper suspension xmember area as that is a 'weak' spot if not spec'd for it.  It is also a spot that can cause beaming and give you front end bounce.  And watch your rail RBM if you hang it behind axle.  There's been some hitch talk here that put RBM well over half, then hang some counterweight and it could put it over.  You are probably somewhere around 1.7-2.1M RBM so calculate your setup, then put in a factor of safety for rusted rails.  Best place is probably near the fwd suspension xmember?

So your spin cast setup for all that work must be the big industrial one with the spin pot that goes in the big washing machine looking tub?  Interesting stuff.  You need to give us a picture tour of it!

Pete good morning,

We configure the Dollytrolley two ways one being with a crude 12 ft wood bed that is so light that three guys can hand carry it and the second is the 20 ft Morgan cargo van body.

Obviously the light wood bed without a load is a rough ride ......

Properly loaded the cargo box gives us a very nice ride because I seek to concentrate the van loads at the extreme ends of the cargo space..... 

Now as some folks may recall at times I become a bit anal about weight and balance calculations regarding truck and trailer combos and this is where we obtain good ride quality by distribution of cargo loads in such a manner to dampen the large air bags by leverage loads instead of large mass loads acting on the suspension....  

Think of the highwire guy with the long balance pole......he uses the long arm length of the pole to dampen his potential out of balance potential.....simple physics......sorta....

I do not recommend my long arm method of load distribution UNLESS one is willing to do the math and work the loads in a proper manner......many folks tend to cut the corners and this can be bad.

Once you start spreading loads over longer arms you need to consider structures and the load paths as Scrap calls out in his comments.......there is little free lunch on the path to a limo ride here.....

Drive on.......(weight....arm.......hey weight a ....moment)

[shorts]

Just my experience, but as Randy suggests a smaller diameter bag with the same as exisiting bag ride/working height dimensions should be readily available, the internal bumper/stop should also be close in dimension to the original, then look for the largest.    available air inlet and you have your desired airbag.  I think the first thing to do to tune the bags would be to install an accurate pressure guage on the suspension side of the ride height valve and monitor the loaded pressure, that pressure and current bag data will get you close to static load on the suspension, then look at the manufacturers engineering data and load graphs to pick a component that will operate in the 50 to 65 PSI range at your desired load,  Probably a $100 to $125 part and then the cost of upgrading to large diameter plumbing and on a singled suspension possibly a ping tank,

[Pete Kildow]

38 minutes ago, Dollytrolley said:

 

Pete good morning,

We configure the Dollytrolley two ways one being with a crude 12 ft wood bed that is so light that three guys can hand carry it and the second is the 20 ft Morgan cargo van body.

Obviously the light wood bed without a load is a rough ride ......

Properly loaded the cargo box gives us a very nice ride because I seek to concentrate the van loads at the extreme ends of the cargo space..... 

Now as some folks may recall at times I become a bit anal about weight and balance calculations regarding truck and trailer combos and this is where we obtain good ride quality by distribution of cargo loads in such a manner to dampen the large air bags by leverage loads instead of large mass loads acting on the suspension....  

Think of the highwire guy with the long balance pole......he uses the long arm length of the pole to dampen his potential out of balance potential.....simple physics......sorta....

I do not recommend my long arm method of load distribution UNLESS one is willing to do the math and work the loads in a proper manner......many folks tend to cut the corners and this can be bad.

Once you start spreading loads over longer arms you need to consider structures and the load paths as Scrap calls out in his comments.......there is little free lunch on the path to a limo ride here.....

Drive on.......(weight....arm.......hey weight a ....moment)

I agree with that. Same as when your able to slide the commercial 5th wheel one notch. And the ride becomes great. But have a load, that  you have to move it forward. And that same truck is going to beat you to death.

As as my Kodiak now, my trailer with extended pin boat. The ride is  great, but yesterday with my Daughters camper. It would beat you to death. Her camper has the old style pin boat. Where it just comes straight down. And every joint in the road slammed me. Sure was glad I had to only move it 14 miles.

The W900l I'm trying to buy. The guy has moved his gooseneck ball back 4". And he told me the trip to Montana before moving it. Everyone in the truck, along with the 6 horses in the trailer had a bad ride. So he moved it back 4" and that tamed the ride.

With the lead I have plans on moving it around to get the best ride. Because weight in the right spots, can help or hurt the ride. The 4 tool boxes on my Kodiak. If I had all the heavy tools in the back boxes. I can tell even with that few hundred pounds. That the ride is better, but move to the forward boxes. And the ride is not near as good.

I'm sure there will be lots of questions on this soon. And I may go with a bed. But have an ideal on how to do it without a bed. And still haul a smart easy.

Pete

[Pete Kildow]

5 minutes ago, shorts said:

Just my experience, but as Randy suggests a smaller diameter bag with the same as exisiting bag ride/working height dimensions should be readily available, the internal bumper/stop should also be close in dimension to the original, then look for the largest.    available air inlet and you have your desired airbag.  I think the first thing to do to tune the bags would be to install an accurate pressure guage on the suspension side of the ride height valve and monitor the loaded pressure, that pressure and current bag data will get you close to static load on the suspension, then look at the manufacturers engineering data and load graphs to pick a component that will operate in the 50 to 65 PSI range at your desired load,  Probably a $100 to $125 part and then the cost of upgrading to large diameter plumbing and on a singled suspension possibly a ping tank,

One issue I know that can come up on the bag sizes. We had to use different bags on an old International one time. Factory bags were not to be found in stock. So we replaced all 4 with some we had in the shop. That truck was scary, I almost rolled it grossing 102,000 lbs with logs. Same hwy, same trailer, same curve, same speed. But different outcome that trip. The bags allows more roll than the factory bags did.

But come to to think of it. I did brag on how great the ride was empty. But loaded it was one of those pucker factory warp 12 rides. We got the right bags out of a junk yard, ran those until the factory bags came in. Someone had taken a knife to all 4 bags. Truck was left on the landing in the woods. And overnight someone took out the bags.

I do feel with our loads this would never be an issue. But same as the old Mack cabover air ride trucks. May let the truck roll and pitch more then we would care for.

But I may be the test dummy on this also. As a buddy of mine owns a big truck yard. And has lots of trashed trucks. And may well be able to try different bags to get the best ride. If I go with a Volvo or Freightliner he has lots of those in the yard. But if I get the W900l, it has new bigger air line bags with it.

[RandyA]

20 hours ago, jeffw said:

PVC for compressed air can be dangerous:

 

http://www.practicalmachinist.com/vb/general/ruptured-pvc-air-lines-what-not-do-230253/

Jeff, yes, those pics are scary.  I am glad your friend wasn't hurt.  Let me throw out some specs and clarification for what I wrote.

First - the PVC in your photos appears to be 1/2" or maybe 3/4" ID.  The wall thickness of either size is 1/8".  I think the max pressure rating is something like 140 psi for cold water, much less for water over 73F.   I would never suggest using this for air pressure lines used with a shop air compressor or on our trucks.  Single stage compressors can run at 130 to 140 psi and two stage can exceed 200 psi.  My truck can reach 110 psi before the unloader kicks in. 

The 4" PVC schedule 40 I referenced has a thickness of 1/4" and is rated for 220 psi at 73F.  The 6" schedule 80 I was thinking about using has a wall thickness of 1/2" and is rated for 470 psi.  I honestly believe one could safely make a ping tank from either one - but I would be using the 6" shown in the photo since it is in my possession.

I appreciate the safety warning - it is relevant for all sizes and schedules of PVC, especially when used in an application like your friend did.

Above:  4" Schedule 40 PVC with 1/4" wall.

Above:  6" schedule 80 PVC with a 1/2" wall thickness.