I will we retrofitting a few feet of foundation where I need to add shear walls for an attic remodel. Here’s the problem- I need to drill through a 2×4, then 8″ of space (rim joist), then a 2×4, then about 7″ of space, then a 2×4, before I even hit concrete. Then I need to drill a 7-8″ deep hole in the concrete. I have looked around and have found SDS Max drill bits that are 3/4″x36″ ($136- ouch). Unfortunately, I only need to drill a few holes, and I own an SDS+ drill, not an SDS MAX.
The solution I will try first is to make a drill bit. I took an sds+ bit, (3/4″x12″), cut off the top and will weld a rod between the two pieces, weld a coupling nut over the welds to reinforce the rod/bit welds, then go at it.
Anyone have any better ideas? I can’t fit a right angle drill in the ponywall space, and I have to drill down and epoxy into the foundation.
Replies
The true value here rents bits like that and so does the bigger tool rental shop, have you looked at trying to rent one?
Never be afraid to try something new. Remember, amateurs built the ark, Professionals built the Titanic.
Welding an extended shaft on your bit is a good way to go (very commonly done on industrial jobsites) if you can't rent one as CAG suggested.
Unless you're a competent welder, however, you'd be ahead to take it to a machine shop or a good fabrication shop. You'll end up with a good weld and a straight bit. Shouldn't cost anywhere near $136.
you can get long sds bits.
i've got a 7/8" one over 3' long.
local tool store should be able to order one.
or take a look here
http://www.boschtools.com/Tools+and+Accessories/Accessories/acc_detail.htm?item_group_id=15461
aleks