How to Build a Clean Box

Sridhar Ayengar ploopster at
Tue Apr 10 01:50:17 CDT 2007

Andy Piercy wrote:
> Alison, thanks for the info, I'll have a go at opening one of the 
> driver, as
> currently they are only as much use as a large paper weight!
> Sridhar,
> A clean box sounda a good idea, could you provide some detaile please?


Basically, the purpose of the clean box is to ensure that the air you're 
working in is clean.  The box should be made from something that won't 
turn readily into dust, for example, it should *not* be made of 
cardboard.  Plastic works best.

Also, the box should have at least one clear side.  I used perspex for 
the sides and top and thick rigid PVC for the base.  It's important for 
you to be able to see what you're working on.

Third, it's important to get the box sealed up well, so use plenty of 
thick silicone sealant along the corners.  And make real sure that the 
silicone is completely and thoroughly dry and set up before you use the 
clean box.  It also couldn't hurt to join the corners on a miter.  In 
mine, I use a false bottom that holds together with some bolts to make 
it easier to open and close the box, so I can get tools and items to be 
repaired in and out of the box.

Fourth, it's a good idea to use an inert gas supply.  For reasons of 
availability and price, the best choice might be nitrogen.  Bottled 
nitrogen won't be completely clean, so an air filter is probably a good 
idea.  Don't use a paper one, obviously.  I use a glass allergen filter. 
  And the gas should go through a regulator.  If it comes out too 
quickly, it could get supercooled, and that would not be fun.  And don't 
forget to create a gas outlet with a one-way valve, to prevent outside 
air from getting in.  If you don't put in an outlet, the gas will find 
its own outlet, and that won't be good.

Obviously, it isn't possible to work in a completely sealed cube.  You 
also need a place to put your hands into the box to actually *do* the 
work.  The most reasonable method for doing this is to attach a pair of 
gloves to the box itself.  Again, getting a good seal between the box 
and the glove is of paramount importance.  Use a sealant material which 
has enough flexibility to do the job.  Also, it would be a good idea to 
have a way of changing the gloves without tearing the box apart.  I 
mounted my gloves to the box on opposite ends of the box so that I can 
get my hands to anywhere in the box.  One thing I didn't think of until 
after I had built the box is that the positive pressure inside the box 
doesn't have to be very high, so you don't have to use gloves that are 
very rigid.  I used pipefitters' gloves the first time, and I lost a lot 
of fine control.  I suggest using something much thinner.

Experiment!  It's the easiest way to figure this stuff out.  And let me 
know how it goes.  I'd be interested to know.  Good luck.

Peace...  Sridhar

>> > So anyway sorry to ramble, After you opened the drive, did you have any
>> > problems with dust and head crashes? Do you think that it would be
>> possible
>> > to fabricate one of these bumpers? Do you have any pictures of this
>> bumper
>> > within the drive?
>> You could always make a cleanbox to do the work in.  It isn't difficult.
>> There are plans available online, but if you have trouble finding
>> them, I'd be willing to describe how I did it.

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