Unihedron

General Category => Weatherproofing => Topic started by: admin on October 21, 2012, 11:30:40 pm

Title: Drainage
Post by: admin on October 21, 2012, 11:30:40 pm

(http://unihedron.com/projects/sqmhousing/housingicon.jpg) (http://unihedron.com/projects/sqmhousing/)

It is important that the bottom of the weatherproof housing must have a drainage hole.
This housing is not hermetically sealed, so any moisture that builds up inside can remain trapped unless the bottom of the housing has a clear hole.
The Unihedron housing (http://unihedron.com/projects/sqmhousing/) does have a hole at the bottom, and the included open-cell foam insert prevents bugs from entering while allowing water to drain.

Title: Re: Drainage
Post by: BPO on February 27, 2014, 09:53:58 am

Hi Anthony.

The base caps of both my SQM-LE enclosures have flexi-conduit connectors fitted, and I suspect they have raised rims internally which prevent any accumulated moisture in the enclosure from draining via the hole. How difficult is it to drill the plastic? Does it crack easily, or is it an easy job?


Cheers,

Gary Roberts
Benmore Peak Observatory
New Zealand

Title: Re: Drainage
Post by: admin on February 27, 2014, 02:00:07 pm

Quote from: BPO on February 27, 2014, 09:53:58 am

The base caps of both my SQM-LE enclosures have flexi-conduit connectors fitted, and I suspect they have raised rims internally which prevent any accumulated moisture in the enclosure from draining via the hole. How difficult is it to drill the plastic? Does it crack easily, or is it an easy job?

Thank you for your question Gary.

The white housing caps (and tube) are made of PVC (http://en.wikipedia.org/wiki/Polyvinyl_chloride). Here are some points below about how I deal with PVC:

• It is a relatively soft plastic that does not crack easily. It might crack if stressed/cut at very low temperatures, but room temperature is warm enough to work with it without worrying too much about cracking.
• The biggest problem I found with cutting PVC is that the cutting tool may grab too easily. I use a dulled drill-bit or hole-saw to prevent grabbing. You can either slightly round the sharp tip edges of the bit with a file, or purchase a special bit for plastic cutting to prevent grabbing (both of which would likely be overkill for your application). Cut at a slow speed, I use 570RPM. Occasionally clean out the excess shavings from the drill bit during use to prevent buildup which will cause the plastic to melt and bind easily.
• I have also had great success with a carving knife. Carve small strips of the plastic to eventually get the shape you want. Box-cutter blades are too thin and sharp to work with nicely, but a pocket knife seems to work well.

If you are adding drain holes, make sure to cover the inside with a screen to prevent bugs crawling back up there.

Best wishes,
Anthony Tekatch

Title: Re: Drainage
Post by: BPO on February 27, 2014, 08:39:11 pm

Hi Anthony.

Thanks for the info. I was concerned I'd crack the plastic and have to buy new ones: Great for you, but not so good for me!

 ;D

Now that I know the plastic likely won't cause any problems, I have hole cutter bits that will do the job easily.

Also, the new holes will be covered by the foam already in the base of the enclosure.


Cheers,

Gary