Constant paint can bulges, what to do?

[peteski]

Sorry, I'm not buying the explanation, other wise the top of the can would show the same dents.

 

Cheers,

Lance

Lance, the top of the can has a different shape. It is not a smooth dome which can be dented as easily as the bottom.

[aurfalien]

Hey Brian, grab a can of your spray paint, that doesn't have any dents in it, shake it as you normally would, and let us know if the dents show up in the bottom. Is it literally every can you use that this shows up?

 

I will, this will be interesting.  I'll also grab my laser heat gun to take readings of the can before and after.

Edited August 4, 2016 by aurfalien

[unclescott58]

You aren't using something like this are you?  I can see the damage your photos showed with this type of rig, especially if it doesn't have a timer on it. 

 

 

Wow! Was that boring. Don't ask this guy time. He'ii tell you how to build a clock.

[peteski]

Seeing the cutaway view of a Tamiya spray can in another  thread reminded me about this problem.  So what is the verdict Brian? Were you able to ease-up in the shaking force and not damage the bottom of the can?

[Harry P.]

I don't think it's possible to shake a can hard enough to cause those bumps. There has to be a more logical explanation.

[mod3l Lover]

    Have they found crop circles or anything of that

nature near your home also?

   Because then maybe we are getting somewhere!

 

   Sorry, I could not resist,

      David S.

[peteski]

I don't think it's possible to shake a can hard enough to cause those bumps. There has to be a more logical explanation.

Well then, it must be supernatural dude!

[Ace-Garageguy]

[Modelbuilder Mark]

Sorry, I'm not buying the explanation, other wise the top of the can would show the same dents.

 

 

I present for my defense, a little video I shot just this morning,around 30 seconds of shaking the can. If the OP shook it longer, the dent could be even worse. Just saying...

https://www.youtube.com/embed/0R6TRP-V4j4

The reason the top of the can does not is the way you shake it, and the shape. The bottom of the can arches up, the ball smacks the side of the can and the bottom and is held there, like a "corner". The top is arched out, so the ball hits it and rolls a bit, and most of us do not shake the can upside down anyway. The way you shake it also matter, like I said too vigorously. It is a little like cracking a whip, it is not shaking it hard so much as yanking the can back up just before the ball hits the bottom.

 

 

Edited September 5, 2016 by Modelbuilder Mark
correct sentence structure

[Foxer]

I find it amazing you can produce those dents ... you provided excellent evidence in the video of what's been talked about here.

I'm a retired Structural Engineer and haven't designed a beam in eight years. I don't want to start in again by calculating the force necessary to deform the dome of the can. Sorry to all those interested and I know this should be the next step in the inquiry.

 

[aurfalien]

Hi,

An update; No more bulges.

I no longer shake the can like a maniac but vary side to side, top to bottom, bottom to top, rotating the can as I shake.

It's working out well for me.

Edited September 5, 2016 by aurfalien

[peteski]

Just as I suspected all along (ignoring the naysayers) - you guys have some really strong arms!   Easy does it!

I'm also wondering if the newer can bottoms (within the last 20 years or so) are made from softer steel (which makes it easier to dent them by shaking).

Edited September 6, 2016 by peteski

[aurfalien]

Just as I suspected all along (ignoring the naysayers) - you guys have some really strong arms!   Easy does it!

Welp, it wasn't how much I was shaking but how hard.  I was slamming the ball against the bottom pretty hard.

Kinda weird to explain.

 

[peteski]

Welp, it wasn't how much I was shaking but how hard.  I was slamming the ball against the bottom pretty hard.

Kinda weird to explain.

 

I know exactly what you mean (the high acceleration of the agitating ballz).

[unclescott58]

 

I present for my defense, a little video I shot just this morning,around 30 seconds of shaking the can. If the OP shook it longer, the dent could be even worse. Just saying...

https://www.youtube.com/embed/0R6TRP-V4j4

The reason the top of the can does not is the way you shake it, and the shape. The bottom of the can arches up, the ball smacks the side of the can and the bottom and is held there, like a "corner". The top is arched out, so the ball hits it and rolls a bit, and most of us do not shake the can upside down anyway. The way you shake it also matter, like I said too vigorously. It is a little like cracking a whip, it is not shaking it hard so much as yanking the can back up just before the ball hits the bottom.

 

 

Wow! I watched your video and I don't get it. In the last few weeks since this thread was started, I've been watching for dents in the bottom of my cans. I still have not gotten any. I don't think your shaking you any harder than I do? I don't know what's going on here. This is weird.

 

[aurfalien]

Wow! I watched your video and I don't get it. In the last few weeks since this thread was started, I've been watching for dents in the bottom of my cans. I still have not gotten any. I don't think your shaking you any harder than I do? I don't know what's going on here. This is weird.

 

Well, Tamiya tech support also said 30 seconds of shaking in my climate should be good enough as it is for them.  Also a more side to side.

I was shaking hard for like 2 minutes.

Edited September 6, 2016 by aurfalien

[Modelbuilder Mark]

Wow! I watched your video and I don't get it. In the last few weeks since this thread was started, I've been watching for dents in the bottom of my cans. I still have not gotten any. I don't think your shaking you any harder than I do? I don't know what's going on here. This is weird.

 

No, not really hard, BUT moving the can in such a fashion that the ball hits the same basic spot repeatedly, coupled with the fact that I "whip" the can back up which then slams the ball against the bottom, rather than "rattling" it.  There were two people that have not yet been back over here to see (or at least not posted in the thread) that were certain it was not the shaking, and I know it sounds silly, but I really want them to see it. LOL

The Testors discontinued line of CreateFX washes and stains in the 1oz glass jars often had little agitators in their bottles. While shaking one of those one day, I cracked the jar, and started to sling paint. I am just glad it did not shatter and send paint flying all over my projects. sooo, I am way gentler on those, moving it around, more of a swishing motion now.

[peteski]

No, not really hard, BUT moving the can in such a fashion that the ball hits the same basic spot repeatedly, coupled with the fact that I "whip" the can back up which then slams the ball against the bottom, rather than "rattling" it. 

You mean the up-and-down hard-stroking motion?  It is a natural motion for male Homo Sapiens.

[Warren D]

I'm thinking that the metal the cans are made from is thinner than it used to be.  I've only had one can pop like that and it was a combo of over-heating and vigorous shaking.  The bottom being concave should be resistant to that but if the metal is thin......

[aurfalien]

I am very happy to report that I can finally immerse my Tamiya paint cans in hot water to achieve fine atomization of the paint.  Totally cool.

 

[Pete J.]

Wow, I just viewed your video and am still stunned.  I tried everything and couldn't get a dent in the bottom of a Tamiya can.  I even tried slamming it down on the bench top thinking that the sudden deceleration may have cause it.  No luck! 

You got some serious moves there man!