[RE-wrenches] Strawbale wall penetration

[William Miller]

Friends:

I keep a set of "grit edge" hole 
saws.http://www.lenoxtools.com/Pages/Product.aspx?id=CarbidegritHoleSaws 
These cut Stucco and plaster without degradation.

If I want to pilot a deep hole, I remove the ~4" pilot bit and chuck in a 
bell hanger bit.  Linked is an 1/4 by 18" bit that will replace the pilot 
bit.  Use with care, this is a long skinny bit. http://tinyurl.com/2cnupu3

William Miller


At 01:36 PM 11/19/2010, you wrote:
>Having a fair bit of experience with bale, I ditto what Bill mentioned but 
>I'll add a simple way that I discovered to getting the inside and outside 
>holes to line up.
>
>Bale walls are seriously thick, so standard extension bits aren't long 
>enough.  I found taking a 2 or  foot length of 3/8" rebar chucked into a 
>half inch drill works nicely for boring a pilot hole all the way through 
>the wall.  Once you have the pilot hole, it's a simple matter of drilling 
>out a hole large enough for your conduit on both sides of the 
>wall.  Either use a small bit to drill a series of holes around the 
>perimeter and connect the dots with a cold chisel, or use a hole saw that 
>you don't mind sacrificing on the plaster.  You don't actually have to 
>"drill" through the entire wall, as the straw can be pushed to the 
>side.  I usually spin the rebar in the hole while chunking it back and 
>forth a few times to clear a path, then thread the conduit through the 
>hole using the rebar as a guide to be able to find the hole on the other 
>side.  It really helps to have a second person on the other side, to help 
>guide it in the final inches.
>
>Rebar as a drill bit also works great with adobe walls.
>
>If you do a lot of this, take a minute to grind down a flat spot on the 
>end of the bar or it will tear up your drill chuck.  Drill chucks can be 
>spendy.  Ask me how I know...
>
>
>Phil Undercuffler
>
>
>
>On Fri, Nov 19, 2010 at 11:27 AM, Bill Hoffer 
><<mailto:sunengser at gmail.com>sunengser at gmail.com> wrote:
>Benn
>I used PVC in the my bale walls with a Junction Box on both sides of the 
>penetration to protect the penetration  (Outside a must!).  I used EMT for 
>all my other wiring, but PVC seems better for an interior to exterior 
>penetration where the heat conduction of the EMT may cause some damaging 
>condensation towards the exterior of the bales.  I used a hammer drill and 
>concrete bits to get through my stucco, it is tough stuff.  I used 2 " 
>conduit so I had to make several smaller holes and knock it out by 
>hand.   I did not have rebar in my bales, but heavyduty 6x6 mesh to get 
>through, as would be expected I never was able to hit the middle of the 
>grid, I just had to cut and hack saw when I hit something, pays to have a 
>sacrificial bit to find the metal.  I then fashioned a home made bit out 
>of the conduit and used that to get through the bales by hand.  That went 
>pretty easy and will allow you to locate the rebar without damaging an 
>expensive bit .  Hard part is lining up to get a good mark on the opposite 
>side.  I used foam to fill any gaps, replastered around the pipe and 
>fitting and caulked really well to seal against water on the outside.  I 
>also located the JB on the outside of the building in a very protected 
>area for additional security.  Water and straw bales do not play well 
>together!  If anything I would favor a slight slope downward on the 
>outside so if there is a leak it will not follow the pipe inward into the 
>bales.
>
>Hope that helps!
>Bill
>On Fri, Nov 19, 2010 at 11:05 AM, benn kilburn 
><<mailto:benn at daystarsolar.ca>benn at daystarsolar.ca> wrote:
>Wrenches,
>Short of contacting the builder, i'm looking for your experiences, 
>practices and "look-out's" for penetrating a strawbale exterior wall with 
>conduit.
>For the project in question there is currently a teck cable from a wind 
>gen entering the home by sharing a HRV vent opening that i want to fix 
>(not my original system by the way) and i will also be adding another 
>penetration for a PV array that i am relocating on the property. The 
>original penetration for the PV was done properly but its not in an ideal 
>location for the re-located array wiring.
>I'm wondering if it is as simple as using a hole saw extension to go thru 
>the ~16" wall and use an LB/box on either side.  I'm sure there is some 
>framework and/or rebar supporting the bales, how do you locate/avoid these 
>when there are no corners to measure from?  (it is a round home)
>Any knowledge if PVC or EMT will react in anyway with the bales?  I'm 
>thinking that PVC would be best....?
>... i am trying to contact the builder to address this, and also to ask a 
>few choice questions regarding the wiring methods (he?) used in the 
>original PV system set-up.
>Cheers,
>benn
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