I drilled a long hole, and it came out wrong

[Rich VanValkenburg]

Today I drilled the last of the floor-to-sternpost holes. So far, I had each one exiting the trailing edge of the sternpost right dead center. This last one was 28" from the floor to the exit. It wound up 3/8" off center.

I took about 2 hours to set up 2 strings that lead from the base of the 'post to the horn about 1 1/4" apart representing the trailing edge to use as a setup guide, then removed the sternpost. The old floor was already drilled, so I passed my long (36") drill bit through so I could see where it would exit the trailing edge relative to the 2 strings, then rigged a jig a foot above the floor to help guide the drill. All looked well, but it's off. Like this-- |O | with the tangent of the hole right at the edge of the trailing edge of the 'post. It's a half inch hole.

The yellow line represents the trajectory of the drill bit. I have to re-drill this thing. No way around it. It has to be able to fit some kind of head within the trailing edge. (The other bolts are carriage bolts with 2 sides of the head ground off.)

Question is, can I use thickened epoxy to fill the hole, or what do I do besides cry over three months of work? I was ready to install.
http://www.imagestation.com/picture/sraid54/p62dc431b34c71f3bdc92ce29b5d6d1e2/fc891a70.jpg

Rich

[Mike Vogdes]

That sucks...
I think your gonna to want epoxy a dowel in that long hole if possible. If not, when you go to redrill the hole thru all that epoxy it will heat up and melt, creating a colosal mess.

Have been following your progress on your project, it looks great. I'm sure you will get over this hurdle.

[Concordia..41]

Mike's dowel idea was what came to mind. Don't worry everything is fixable.

Nothing this long, but Dave's done some doweling in places. I'll have him chime in with what worked and what didn't when he gets home.

Sonya's my second favorite wood boat ;) and the shot of her in the slings is on my computer wallpaper as we speak (write).

It'll be ok smile.gif
- M

[videoguy]

Bummer Rich I wonder is it possible to redrill starting from the exit point and meeting the
Existing hole somewhere around the midpoint and after the bolt is in fill the bad hole with
Thickened epoxy? ........Phil

[Harry Miller]

What a revoltin' development this is. The Great Guildersleeve said this line at some point in every one of his radio shows. (You have to be a certain age) and he sure would have said it here!
This may be akin to closing the barn door after the horse is gone but have you considered a boring bar? I've not used one myself but then again I haven't had to drill such a long hole. check it out at: Paul Gartside Ltd (http://www.gartsideboats.com/boring.php)
Yesterday I would have put LOL here because I thought it meant Lots of Luck. Laugh out Loud is the surely the furthest thing from my mind.

[whb]

Rich,

I think there are many possible solutions.

Here's a thought.

Take a rod the length of your hole plus 10" but say 1/8 less in diameter.

To this rod epoxy some garnet grit say 30 grit. Leave three inches unepoxied on one end and 7" on the other. You've just created a real long drum sander. There might be better choices on the glue to use?

The drum sander will be about the width of your desired hole.

Chuck the 3" end into your drill and set for low speed.

Insert in the hole with the drill at the end where the hole is where it should be. A second person will hold onto the long end with some cloth on the smooth ungritted 7" part and pull it back to where the hole should be. This will create a tapered hole that is perfect at one end.

Then insert a rod the same diameter as the bolt coated with a releasing agent. Finally fill the remaining space with long tapers and epoxy. Take out the rod and put in your bolt.

My concern with putting in a dowel and redrilling is that it is going to be very hard to keep the drill straight as the dowel and epoxy will deflect it. This might be less so if you can make a dowel from cast offs of this same piece of wood.

Good Luck

Howard

[ 03-08-2003, 06:06 PM: Message edited by: whb ]

[imported_Conrad]

How about forgetting the bolt and filling the hole with a drift- it certainly is long enough to provide the holding power you need. Or cut the bolt short and epoxy it in- you'll never pull it out with that length. The idea is to fix the bits of wood together, not achieve some concept of perfection.

[fair&fair]

The dowel idea is perfect. It is quick and simple.

[JeffH]

Just learned this trick myself, when I had a dull drill bit wander off when drilling through the sheer clamp for the deck beam bolts (well, that was part of the problem. The other part was that I just messed up). Find a piece of scap of the same material that you were drilling through. Cut it to 1/2" square (or whatever size hole you were drilling). Cut the square piece roughly to the length of the hole plus a bit more. Take a hand plane and knock the square edges off (but don't overdo it.. Roughly round-ish but still larger than the hole). Find an odd piece of 1/4" steel and drill a 1/2" hole in it (or whatever size hole you're plugging). Dabble a little glue in the hole, place the steel piece flat over the hole so that the holes line up. Pound the planed-off piece of wood through the steel and into the hole. Wait for glue to dry, cut the top of the plug flush and re-drill. Be very careful and drill a little at a time and clear the hole frequently. Works like a charm :D

Jeff

[ken mcclure]

Sounds like a wild goose. About 3/8" off-center.

[Dave Fleming]

What kind of bit and you DID drill a pilot hole of the same diameter first right?

[rycophyla]

I've been very interested in reading the suggestions for solutions to the problem . . . and I'm sure glad I'm not the one to take care of it. I fear it is beyond my experience/skills. HOWEVER, I would humbly suggest that it was "The Life of Riley" which featured the phrase, "What a revoltin' development this is!" William Bendix played the part on the old TV show - and I think also played it earlier on the radio.
Ed

[Paul Scheuer]

Bummer. But it could have been much worse. You could have busted out the side of that beautiful timber.

Since you've already got the idea of asymetrical heads, how 'bout a "special" head for this one also. I'm thinking of welding a short cylinder, off center to the end of your bolt, and drilling a matching, centered recess in the exposed end of your timber. A hex recess in the off-centered head, to keep it from rotating while you torque the nut might be a good idea.

With a nice, centered bung, no one will ever know.

[Harry Miller]

You're right Ed. I'm :confused: It was Riley who said "What a revoltin' development this is" This doesn't change its relevance here though.

[Rich VanValkenburg]

Nice comeback. Thanks to all.

Dave? Pilot hole same size? It's a new twist bit with a turned down shank welded to a lathe-bored 3 foot piece of cold-rolled. The guys that made it also make custom cars and they said they wanted it to be a precision tool, so no way would they just butt-weld it.

I've been thinking about the drift idea, and also about making a new floor and redrilling at a different angle like the purple line in the pic. Boyohboy, the things that can wake you out of a sound sleep.
http://www.imagestation.com/picture/sraid54/p47fd9b040e453d9e393f72f20e2f8adf/fc883052.jpg

In any case, the dowel is going to be trouble because the oak is still green inside.

Rich

[ken mcclure]

!!! Maybe you could make a dowel out of green wood?

[Scott Rosen]

A dowel could be tricky because the grain orientation may be different from the floor timbers. That could make re-drilling a straight hole even harder the second time around.

[Rich VanValkenburg]

What makes this so hard to swallow is that I changed the way I normally drill for long holes because I didn't think I'd get it right.

What I've been doing is to make a 'target' piece out of 1" x 1/4" about a foot long, and marking dark lines every 3/4" and labeling it 5..4..3..2..1..0..1..2..3..4..5. I mark the 0 line on the reverse side and nail it at the exit point with the lines facing up so I can see it from inside the boat, then sight down the drill bit using the 'target' piece to guide it. Every hole I've drilled this way has come out right on. I'll do the next hole this way.

Yesterday I was doomed to fail from the start. Everything that happened said "don't drill it today, go home and have a beer and watch a hockey game". First, with all of the pieces ready and tools inside the boat, I went up the ladder...and had to go down because the extension cord slipped and fell out. Back up the ladder. Forgot the chuck key..back down the ladder. Accidentaly knocked one of the clamps loose. Back down the ladder. Lost the extension cord again....get the picture? I've gotta learn to pay attention to those subliminal messages.

Thinking about the drift. Well, the sternpost isn't completely faired down to plank thickness. I cut the rabbet using the fair line of the flow of the frames to determine the depth, which gives me some extra sternpost to shave down after the planks are in. Doing that will expose the drift at the trailing edge, I think.

Rich

[Paul Scheuer]

Ouch. Two thoughts -

Can you build a "rear sight" perfectly positioned above the start of the hole to locate the drill and improve your aim?

When I did my deep hole, about 30 inches through the butt-end block of a hollow mast, I used a small light bulb, from my son's train set, that I fed into the hole periodically to check my progress before it was too late to make any corrections. With it I could see where the bottom of the hole was going.

Good luck.

[Dave Fleming]

Dave? Pilot hole same size? It's a new twist bit with a turned down shank welded to a lathe-bored 3 foot piece of cold-rolled. The guys that made it also make custom cars and they said they wanted it to be a precision tool, so no way would they just butt-weld it.
OK, this is a good expample of terminology that I was referring to in my recent post.
What do YOU mean bye a twist drill? All or most all drill bits have twist but please be more specific.
Bye 'pilot hole' I mean using a 'jobbers long length metal boring bit' say 8 to 10 inches long with the cutting lips ground for wood NOT metal. The cutting edge angles are different see: Machinerys Handbook. This gives you a nice straight on start for the rest of the deep hole boring. Please get back to us on this.

[Rich VanValkenburg]

Dave, I guess I should have read this first-- http://media5.hypernet.com/cgi-bin/UBB/ultimatebb.cgi?ubb=get_topic&f=1&t=001549&p=

Rich

[Lulworth]

Rich,

I don't get the problem (but then I'm a bit of a carpentry hack). If it were me I would counter sink the exit end enough so that the head of the bolt lies clear of the sides (even if you have to reshape the nut/bolt head) and thank your lucky stars it wasn't 2" off and emerging from the side of the rudder post like a zit on a teenager. The other possibility would be to drill from the rudder post side until you meet the hole (as suggested above). The bronze will bend to accomodate the small change in angle if driven in with a hammer. Advice from one who doesn't really know so take it for what its worth...

David.

[imported_Conrad]

A drift only has to hold the floor, and doesn't need to go all the way to the bottom of the hole. Put some other bolts/drifts in at a more appropriate angle if you're concerned about holding the deadwood together. The angle of this bolt seem a bit odd to me anyway, too close to the direction of the grain to really have a whole lot of strength, plus it will want to pull the bits of deadwood along each other as much as together. Fasten the floor with a drift/epoxy, then put in some more at advantageous angles to hold the deadwood. Plug the part of the hole you're not using with a dowel or epoxy poured from above against a short plug. It's only one floor/frame/keel joint- the boat isn't going to fall apart, but you could always set a second floor next to it, bolted to the first, and pin it with a drift or two also, at divergent angles. That would hold it! :D

[David N.]

Good idea about the " target Board " , to take that one step further one could attatch an "el cheapo" laser to the drill , with a stand off bracket ( say to the rt angle handle ) , then measure the offset from the drill , your offset then becomes a given on the target board . The laser and bit can be centered out over the distance of the bitt , so you run true .

This idea just came to me and I have not tried it out , some roto hammers have depth gauges on them and that too was part of the thought process .

Your so right about those little voices .

[Concordia..41]

Rich
I have had to dowel a few misaligned holes over the years and yes it does seem that you get tired, things just are not going right and you just want to get something done and you end up doing it again.
3/8” of an inch is not far to be off over 28” and should be able to be corrected for. I would remove the floor and drive a loose fitting dowel, preferably made from the same wood used for the sternpost into the sternpost, one that could be easily driven back out, not gluing it. Then drill a small pilot hole from the bottom of the sternpost and see how close I could get to the center of the top hole. If you are not close enough you can drive it back out and try again. When you do get it close enough you can drive the dowel out apply the glue and drive it back in. Then drill the hole. Over that distance a ½” bronze bolt should curve enough to follow the existing hole in the floor.

Dave

[brian.cunningham]

OUCH!
Sorry to hear Rick. :(

Hope you find a easy solution.

[Art Read]

"...Over that distance a ½” bronze bolt should curve enough to follow the existing hole in the floor...."

Not long ago, RGM was telling me about having to drive some replacement keel bolts through some "creatively" bored holes that had some pretty extreme "wiggles" in 'em. Perhaps just "fixing" the bottom few inches and blending into the original hole as suggested above would be the lesser of two evils?

[Alan D. Hyde]

What's wrong with Howard's idea???

It makes sense to me.

Should be strong, and relatively fail-safe, shouldn't it?? Or am I missing something?

Dave? Anyone else?

Alan

[RalphS]

A little late but WB #128 had a good article on drilling long holes.