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hazmat, scale modelling style

Posted: January 26th, 2018, 10:54 pm
by rob_van_riel
So, I had these rather nice Gunze jars of paint. More than decent paints, easy to use screw top glass jars.
Easy to use, except that the slightest bit of paint in the threads will cause them to seize up. As in, nothing short of a pair of water pump pliers will get the jar to open, and even those struggle to get a good enough grip on the glass. So you squeeze, hard.
And then the bottle collapses, effectively exploding, and showering everything in a mixture of fast drying dark grey paint and splintered glass. Everything in this case of course includes the idiot trying to get the jar open. Splintered glass all over yourself and your surroundings is entertaining enough when dry, but that doesn't hold a candle to sticky splintered glass.

Enough modeling for today :evil:

Any better ideas for getting a sufficiently strong grip on glass jars much appreciated :cry:

Re: hazmat, scale modelling style

Posted: January 26th, 2018, 11:03 pm
by iggie
I always had this problem with the old Airfix glass bottles; I used to gently squeeze the cap in the gap between the pantry for and it's frame (hinge side) to hold the cap while I turned the bottle to break the seal.... never had one break

PS I hope you didn't get any glad in your eyes :shock:

Re: hazmat, scale modelling style

Posted: January 26th, 2018, 11:13 pm
by rob_van_riel
iggie wrote:PS I hope you didn't get any glad in your eyes :shock:
Gravity was on my side, initial energy of the glass splinters/paint mix was quite low of course, and I'm never without my glasses. No damage to my person... so far. I've decided to write of one set of pajamas (I realised there was something I should have done before going to bed..), since I don't particularly fancy sleeping in pajamas with (possibly detachable) razor sharp glitters on them, but writing off the floor on the room and the workbench is another matter. This may come back to bite me later.

Re: hazmat, scale modelling style

Posted: January 27th, 2018, 12:00 am
by DavidWomby
I have same problem with Gunze (and other bottles). What works for me is place the bottle cap side down in very hot water for a few minutes. Then remove and, grasping cap with a rag (to stop hand slipping), unscrew. Either the heat expands the cap faster than the glass or it's softening the paint on the threads but I have always got them open in the end this way.

David

Re: hazmat, scale modelling style

Posted: January 27th, 2018, 12:06 am
by 59North
Wrapping a wide elastic band around the bottle lets you have a good grip on the glass. Then, I use the water-pumps on the cap. Usually works for me.

Re: hazmat, scale modelling style

Posted: January 27th, 2018, 2:23 am
by general rocket
I'm with dwomby. Run the hot tap or boiling water from the kettle, then grip it while wearing a pair of marigolds and it"should" open quite easily.

Re: hazmat, scale modelling style

Posted: January 27th, 2018, 2:59 am
by JohnRatzenberger
I use the warm water to loosen things up.
Then put the pliers near the very top of the cap, not on the threads.
Then while holding the pliers firmly but not tightly, twist the bottle with your other hand using a rag around the bottle if needed.

Re: hazmat, scale modelling style

Posted: January 27th, 2018, 5:10 am
by Kitaholic
+1 on the hot water method

Re: hazmat, scale modelling style

Posted: January 27th, 2018, 8:26 am
by spitfire1677
I use one of Mr Hobbys cap opening tool, LINK, if you shop about you can get them a wee bit cheaper.

Re: hazmat, scale modelling style

Posted: January 27th, 2018, 9:46 am
by Dazzled
I use a cheap pair of water pump/swan neck pliers but only, I repeat ONLY, on the lid, never on the glass. If I need some more purchase on the jar I usually use a dry cloth or some rubber gasket material. If you need to grip the jar hard I suggest a rubber strap wrench (which is a real tool and not something sold in Anne Summers), also known as a "boa constrictor' wrench. They're intended for use as an aid to removing oil filters but can be found in small enough sizes to work on small paint jars.

Re: hazmat, scale modelling style

Posted: January 27th, 2018, 11:32 am
by ShaunW
I have come across this issue quite a number of times over the years as a long time user of Tamiya acrylics. I have an old device that is designed to remove tight lids from things such as jam jars, which is adjustable for various diameters of lid/tops and most of the time it will remove the recalcitrant top. When a top is really gummed up and refuses to yield to the jam jar opener, however, I'm another devotee of the hot water method as a last resort and so far it hasn't failed.

Re: hazmat, scale modelling style

Posted: January 27th, 2018, 1:42 pm
by DavidWomby
spitfire1677 wrote:I use one of Mr Hobbys cap opening tool, LINK, if you shop about you can get them a wee bit cheaper.
Good grief! Seems there's a tool for everything now. Mind you, the suspicious part of my mind is wondering if some product management person somewhere said "and if we make the caps hard to get off, we can then increase our profitability by offering an extra cost tool to open it". :ha:

David

Re: hazmat, scale modelling style

Posted: January 27th, 2018, 1:57 pm
by Kitaholic
I'm sure I saw something similar to that in Poundstretchers or Wilkos for a fraction of that cost

Re: hazmat, scale modelling style

Posted: January 28th, 2018, 5:28 pm
by Eric Mc
I pour some boiling water into a shallow dish and place the jar inverted into the water. I just put enough water into the dish to cover the plastic lid. I leave the bottle alone for about thirty seconds. You can actually hear the solid paint crack and release the lid.

Remove the bottle carefully (the jar will have got quite hot) and twist the lid in the normal way. I find the lid will have released sufficiently for it to rotate without too much effort (I'm the proverbial 7 stone weakling - although I'm not really 7 stone :)).

Re: hazmat, scale modelling style

Posted: January 28th, 2018, 7:10 pm
by rob_van_riel
Hot water seems to be the way to go here, but I find it unattractively cumbersome.

I think I'll try an experiment with an old inner tyre. The ones for a normal bicycle are too small, but there should be a size that is a very tight fit around a Gunze/small Tamiya jar. Ideally, it should only fit when the rubber is a bit stretched. If I can find a good size, a single tube should last forever; there's a lot of 15mm bands in one.