Hi All,
It’s been awhile since I posted, hope the discussion title peaked your interest. I’m building the concrete forms for the foundation since I can’t seem to rent them. My friend doing the job said a 4×8 sheet of ply will need a total of 10, 5/8 inch holes per sheet for the form ties. In an effort to save time, can anyone recommend a quick way to do this? They’ll be stacked either on my truck or at the site, about 19″ tall. Thought I could possibly go through 5 sheets or so with a spade bit, or speedbor bit, remove those sheet and continue till done.
Thanks
Kevin
Edited 5/19/2007 5:50 pm ET by dockelly
Replies
Dock,
I have used a long self feed auger bit for this.
Electrical , plumbing supply stores if the local LY doesn't have one.
A warning however, to do this you must get your drill perpendicular to the sheets in two axis and keep that way . Easier said than done, if the bit isn't held right the sheets on the bottom will have holes that won't align with the sheets on the top of the pile.
It actually works best using this long a bit if you stand sheets that were next to each other in the pile across from each other for the form, that way any wander in the drill bit is minimized by having the "wandering" holes facing each other in the correct order.
Some misalignment won't hurt when it comes to snap ties, but get off by more than say an 1" and things get tougher to make work.
I thought about the wiggle factor, actually wondered if I could somehow attach drill press to wood. More I thought about that, the more I thought I'd be creating work when the goal is to cut down time involved.
Dock,
I have used shorter auger bits as well.
I think it is a matter of choose your poison, move sheets and drill , or have a few holes wander.
I have done "bunks" of 3/4" ply this way , drill as deep into the pile as I could with a 16" bit, remove the drilled sheets, re-layout the holes to correct any wander and drill again.
A couple of squares set up on the pile to act as visual guides for the bit helps immensely.
"Poor is not the person who has too little, but the person who craves more."...Seneca
"choose your poison"Yeah, that's what i was thinking. Thought I'd throw it out there, see if there were any quicker ways. I'll probably end up spending more time discussing it here than it actually takes.Thanks
Kevin
I use an auger bit for the exact application you're describing, but I would never tackle 30 sheets at a time because, with the variations found in plywood (knots, core gaps, varying wood densities, etc.), it's pretty much shear luck to get a perfectly straight hole.
I usually do about 6 or 8 sheets at a time....I use a long (3/4" X 24") bit and, if I have a lot of panels to do, just build a quicky guide out of scraps that will align the bit perp. to the sheets.
Sometimes, it helps to bar clamp your stack so the wandering bit doesn't misalign your stack (especially if your bit is a little dull).
As someone mentioned, a little misalignment is OK, but if you're off very far it can be a PITA, especially if a rebar is standing in the way.
There is a drill made, that has a round bubble level built into the rear of the drill.
When the drill is being used to drill straight down like you are, that bubble will tell you when you get out of plumb in any direction... Long as your stack was perfectly level both directions, you should be able to keep the hole pretty much where you want it all the way through.
I have no idea what the drill is. My memory isn't THAT good.
;o)
Maybe you could epoxy a cheapo bubble level to the back end of your own drill.
Chuck the drill to a rod that you have clamped up in a vice. Make sure the rod is perfectly plumb in every direction. Leave enough rod to go completely into, and bottom out in the drill chuck.
Now it's up to you to figure out how to build up the back end of the drill case so that you can epoxy the bubble level there and keep it level as it cures.
Might be kinda dumb to do all that for a single job. But it would obviously be handy in a lot of other situations as well.
There ARE regular drill bits made in longer length. Usually find them near the electrician's tools. I have a 5/16" bit that is at least 18 inches long.
Add together, that 18 inch bit and the bubble level, and you can do the job in two stacks.
I own that sort of drill, my cordless I think.
Thanks
Cool !
There are a lot of drills made now, that have a level on the top.
But not many have that bullseye level on the back.
Here's a bullseye level for less than 5 bucks for anyone intereted in setting their drill up with one...
Bullseye
I vaugely remember another regular poster here telling about how they did this a couple years ago.
Edit: I checked the shipping. This 2 dollar and fifty cent level becomes nearly ten dollars once shipping is added.
Fight fire with water.
Edited 5/19/2007 9:24 pm by Luka
Kelly,
I know it sonds counter-productive, but I reccommend that you build the forms before you drill.
The end offsets are different for inside and outside forms. We always marked the end forms and the field forms as to inside end, outside field, etc.
SamT
Praise the Corporation, for the Corporations' highest concern is the benefit to the people.
Hey Sam,
That thought did occur to me. I have no electric at the house, disconnected per BI to get permit for lift. My neighbor has graciously volunteered his power, but I thought about buying a generator just the same. I'm overdue for a new toy. I'll discuss it with my concrete guy.
Thanks
Kevin
With a sharp spade bit boring one sheet at a time takes less than two minutes. This includes snapping or scribing two lines and measuring for tie holes laterally.If the system is snapties and hairpins, then 8 holes are needed.I imagine you may be using the Gates system,ten holes but the tie holes are 13/16" not 5/8". The eye end of the tie where the dog clamps won't go thru a 5/8" hole.
In any case the absolute fastest and most accurate way is one sheet at a time. You bore off the stack, put donnage under a sheet then bore.I prefer to place a dozen or so sheets on horses, short 2x or 4x4 under each end.I scribe the long sides, measure the centers and drill.It takes I guess 3 or 4 seconds to bore each hole. I never actually timed it,goes to fast to even bother.
If you decide to stack and multiple bore, you'll be sorry.You will spend a lot of time lining up the sheets,tacking them or clamping together.Then finding out that the top sheet and maybe the second sheet are the only ones that are correctly bored.
mike
Hey Mike,
That's what I was thinking, actually it's 8 holes at 1,3,5,7 ft. I'll just do it on site. 30 sheets with holes not lining up would add to the work, to risky.
Kevin
Make a template to clamp down and drill through it, one sheet at a time.
Mike's excellent explanation describes the accepted method for speed and accuracy. Key points are "sharp spade bit(s)" and scribing off the long edges. Wear a leather glove on your off hand or wrap some electrician's tape around its index finger, to protect from splinters. I prefer tape.