• Thanks for visiting The Penturners Forum today.

    There are many features and resources that currently you are unable to see or access, either because you're not yet registered, or if you're already registered, because you're not logged in.

    To gain full access to the forum, please log in or register now. Registration is completely free, it only takes a few seconds, and you can join our well established community of like-minded pen makers.

Vacuum chamber lid shattered!!!

Bucks

Fellow
Joined
Apr 26, 2016
Posts
1,425
Location
North Yorkshire
First Name
Paul
Just had the 20mm thick acrylic lid on our vacuum chamber shatter whilst stabilising some pen blanks, anyone have any suggestions on where we could purchase a piece of 30mm or even 40mm thick acrylic & have it machined? Not sure on trying to machine a piece myself as if it goes wrong it's a expensive mistake!

IMG_5104.jpg
 

Phil Dart

Moderator
Executive Member
Joined
Nov 28, 2014
Posts
5,455
Location
Colebrooke, Devon
First Name
Phil
Bloody hell Paul!! That doesn't sound good. If you were working within tolerances, does the manufacturer/supplier not have anything to say on the matter? - like sorry, here's a replacement.
 

Bucks

Fellow
Joined
Apr 26, 2016
Posts
1,425
Location
North Yorkshire
First Name
Paul
I've just emailed HVAC store the supplier of the vacuum chamber, see what they have to say tommorow, but I recon a replacement 20mm lid will probably go the same way! That's why I'm trying to get a 30-40mm lid made from somewhere.
 

Penpal

Grand Master
Joined
May 26, 2013
Posts
25,340
Location
Canberra AUSTRALIA
First Name
Peter
In America the main dealer in stabilising fluid recesses his units down to the lid height following the implosion of tops etc over time. Seemed like a good idea to me. Many users had made Corian tops that fractured also. Recommended pressures are important to follow. On the IAP in their library these probs etc are covered in detail. What may appear substantial can be deceiving when subject to stress. Mesquite Man is the expert. Curtis Seebeck.

Peter.
 

Bucks

Fellow
Joined
Apr 26, 2016
Posts
1,425
Location
North Yorkshire
First Name
Paul
To make matters even worse we also use the vacuum chamber for degassing the silicone for our moulds so, getting something sorted it pretty urgent
 

Bucks

Fellow
Joined
Apr 26, 2016
Posts
1,425
Location
North Yorkshire
First Name
Paul
Yeh Peter, I've been chatting to Curtis @ Turntex this evening for quite a while, he's been very helpful & made me realise that the 20mm acrylic lids on a 260mm diameter pot aren't suitable for the constant vacuum that stabilising requires, as I found out earlier this evening!
 

Bucks

Fellow
Joined
Apr 26, 2016
Posts
1,425
Location
North Yorkshire
First Name
Paul
Thanks guys for the links I have managed to order one from here £70 delivered for 30mm thick machined round with polished edges & drilled, so hopefully that will be a lot stronger than the origionaly supplied 20mm
:fingers:
 

Bucks

Fellow
Joined
Apr 26, 2016
Posts
1,425
Location
North Yorkshire
First Name
Paul
Snippet from a conversation I had with Curtis last night, as predicted the person I spoke to at HVAC Store tried blaming the CJ, i've emailed them this snippet from Curtis & waiting to here from someone higher up.
Image 68.jpg
 

Graham_C

Fellow
Joined
Feb 1, 2017
Posts
1,153
Location
Tywyn
First Name
Graham
Flipping heck. Just looked at my BRAND NEW lid - used twice and there are tiny fractures around the hole! :vangry:
 

Bammer

Fellow
Joined
Oct 5, 2015
Posts
1,482
Location
Cambridge
First Name
Brad
HVAC lids are crap, the stress points where they drill through do not help with this. They offer to replace them with the same stuff ...

DO NOT ever pick up the lid using the fittings, this will add to the stress
 

Bucks

Fellow
Joined
Apr 26, 2016
Posts
1,425
Location
North Yorkshire
First Name
Paul
HVAC lids are crap, the stress points where they drill through do not help with this. They offer to replace them with the same stuff ...

DO NOT ever pick up the lid using the fittings, this will add to the stress

Thanks for the warning Brad, do you recon 19mm thick glass 280mm diameter with 2 10mm holes in will be suitable?
 

Bammer

Fellow
Joined
Oct 5, 2015
Posts
1,482
Location
Cambridge
First Name
Brad
Thanks for the warning Brad, do you recon 19mm thick glass 280mm diameter with 2 10mm holes in will be suitable?


No Idea about glass, I got one machined out of 20mm Ali ... overkill, can't see whats going on but then I know whats going on :winking:
 

Bucks

Fellow
Joined
Apr 26, 2016
Posts
1,425
Location
North Yorkshire
First Name
Paul
Wow the 19mm thick glass was going to cost £225 so I'll stick with the 30mm thick acrylic for £70 that I had ordered earlier.

HVAC store admitted it was probably due to dodgy drilling, as it has hardly been used for cactus juice & there would be signs of crazing (my words as can't remember exactly what she said over the phone lol) they are sending a foc replacement lid out, so hats off to them for not blaming the cactus juice on this occasion! She is adamant that she's seen quite a lot of reports stating that cactus juice & similar products are known to atack acrylic though.
 

Treeesa

Graduate Member
Joined
Oct 5, 2014
Posts
855
Location
Berkshire
First Name
Andy
Try Lexan or any other polycarbonate Paul, it's what they use for Police shields , Windows etc - I wouldn't pay to have it cut either as you can easily cut it on a bandsaw and it won't shatter when you drill it. It ain't cheap but then it ain't acrylic. I used 12mm and left the polythene scratch film on
 

Penpal

Grand Master
Joined
May 26, 2013
Posts
25,340
Location
Canberra AUSTRALIA
First Name
Peter
Quite a crusade this, a lot to be considered along the way with claims and counter claims in every direction. Full marks to HVAC for the replacement lid.

Peter.
 
Warning! This thread has not had any replies for over a year. You are welcome to post a reply here, but it might be better to start a new thread (and maybe include a link to this one if you need to).
Top