Screwed up my bench dog holes

[Tom Miller]

AAAAAAAAAAAARGH!!!

After taking forever to decide on the placement of dog holes in my 3 layer mdf benchtop, I got impatient in the execution phase. I had planned to get a 3/4" bradpoint bit, and make a guide out of 2" hardwood on the drill press to make nice, vertical holes. Instead, I decided that my little portable drill guide and a 3/4" forstner would do.

The first hole was, how shall we say, not at ALL vertical. So, in frustration, I figured I could do way better free hand. Well, turns out I can't. But maybe with lessons learned on that hole, and lots more frustration, the third would be better. Nope. In fact, it was worse. Imagine my surprise.

I know that some people advocate tilted dog holes. But no one that I know of advocates tilting at random angles in random directions.

Luckily I stopped at 3 (that's right, 3!) holes. [B)] (Came close to going Swiss cheese on its @ss!)

I think I'm gonna make some mdf plugs, fill the holes, and try again. Maybe even with a bradpoint drill bit this time. [:I]

Thanks for listening.

Regards,
Tom

[RodKirby]

I used a 3/4" twist bit (3/8" shank) - slow speed! Worked just fine.

[Scottydont]

I did mine freehand with a bradpoint bit without problems. In my case I have laminate flooring sandwiched with 2 3/4" MDF layers. The laminate is touch enough that it keeps the bit from walking in the hole going throung the MDF.

On another bench I used twist drill bits with pilot holes. I like that method over the bradpoint.

Another thing you can do is take a block of wood and drill it on the drill press then use the block as a guide to do them freehand.

Sounds like it's water under the bridge at this point though.

You could cover your bench in laminate flooring trim it out and redrill your bench dog holes in a different location. (No one will know but us!)

[Tom Miller]

Thanks, Scott and Rod, for the twist bit recommendation. I had originally ruled out a twist bit thinking they'd leave a nasty entry wound. Now that I think of it, if I clamp down a 3" thick piece of hardwood with a 3/4" guide hole, that would prevent any entry wound.

First, I'm going to try turning some 2.5" long 3/4" diameter plugs from mdf to patch the holes. That should be interesting. Keep an eye on this thread to see what stupid thing I do tonight. [B)]

Regards,
Tom

[softop41]

I used a a 3/4" forstner freehand in my MDF top and am very happy. Perhaps it is because I only had 3/4" to go through but I had a lot of them because I was making my own imitation of the Festool benchtop that allows you to clamp internally (with their special clamps) as well as around the edges.

[Tom Miller]

quote:Originally posted by softop41

I used a a 3/4" forstner freehand in my MDF top and am very happy. Perhaps it is because I only had 3/4" to go through....

I think you're right about only going 3/4". I've been thinking about this a little more, and I've come to the conclusion that I was more than a little, uhhh, let's say "unwise" to try the forstner freehand on a 2.25" bench. In other words, I didn't have a chance of getting a straight hole.

As I see it, there's very little depth to the 3/4" part of the bit to keep it going straight, compared to a twist or brad point bit. Even if I was holding the drill perfectly straight, any sideways forces (applied by me, or the material I'm drilling) could cause the bit to wander much easier. An analogy to bandsaw blades would be the difference between an 1/8" blade and a 3/4" blade, and their ability to cut curves.

I turned some 2.5" long 3/4" diameter plugs from 3/4" mdf last night, and glued them in. It worked flawlessly.

I checked HD for a 3/4" twist bit, but it was too short. I want at least 6" so I can use ~3" deep guide, with >2.5" left for drilling.

I'll check the local Seven Corners Hardware today (think Woodcraft on steroids) -- they'll have a few options to choose from.

Regards,
Tom

[LCHIEN]

just a thought - are there any straight 3/4", plunge-cutting router bits you could use with a plunge router to make these holes nice and vertical?

http://www.mlcswoodworking.com/shops.../bt_plung.html

One like this, and an indexing guide that fit into the previous hole would yield a string of equispaced holes quickly without measuring or marking. I can explain or illustrate this guide if you need more detail.

[Tom Miller]

Loring, I had considered that option -- I think it would probably yield the best (most vertical and smoothest) dog hole. I wasn't sure I could have gotten the required depth, though.

Anyway, problem solved as I found a 6" long, 3/4" bradpoint bit. I used a 2.5" thick guide block that I drilled on the DP, and clamped to the workbench. I used the same entrance hole, so the only sign of my error is on the bottom of the bench.

I've already used the dog holes a couple times this morning. As usual, I can't believe I waited this long!

Regards,
Tom

[MBG]

Tom - I had similar problems on my workbench with that had 3-layers of hard particle board. I finally found use for my 1" HF SDS rotary hammer-drill that I got for almost nothing. It was the only tool that could cut through the top w/o burning the bit. BTY I had 48 holes to drill.


Mike

[kyle.w]

you should have not used the cordless drill for that. that must stink. sorry

[BobSch]

[quote]quote:Originally posted by Tom Miller

Originally posted by softop41



I'll check the local Seven Corners Hardware today (think Woodcraft on steroids) -- they'll have a few options to choose from.

Regards,
Tom

You talking about the Seven Corners Hdwe in St. Paul? Talk about a purveyor of fine tool porn, whew. I try to stay away from there... dangerous to my financial well-being, you know.

[Martin]

look on-line at Enco
http://www.use-enco.com/CGI/INSRHM
look at single end end mills. 1/2 in. shank, 3/4 in dia. at least it will give a 1 5/8 in. hole in the plunge router. sometimes you can find a 6 inch end mill
machine tool bits can sometimes used for making mortises
I used one in my drill press making some mortise in timber frames and later learned a guy at work did the same thing[)]

[Tom Miller]

[quote]quote:Originally posted by BobSch

quote:Originally posted by Tom Miller

Originally posted by softop41



I'll check the local Seven Corners Hardware today (think Woodcraft on steroids) -- they'll have a few options to choose from.

Regards,
Tom

You talking about the Seven Corners Hdwe in St. Paul? Talk about a purveyor of fine tool porn, whew. I try to stay away from there... dangerous to my financial well-being, you know.

That's the place! When I bought my bandsaw there, I called ahead to make sure they had one in stock. They had 30.

Regards,
Tom