Drilling holes???

[DPeterson]

Drilled a couple holes in the transom of my Woodstuff tunnel a couple days ago for my steering boots. After building boats for 10 years I still can't seem to drill holes without splintering the wood or chipping the glass. Really pisses me off. What is the secret? I have done the tape procedure also and that didn't seem to be the cure all. I did have some better success with drill bits designed for plastic and have just ordered some bits specifically designed for acrylic. We'll see if they help. You guy's have any drilling tips?

Thanks - Doug

[Steven Vaccaro]

I've only had real good luck when drilling a smaller hole, then use a reamer.

[JimClark]

Dull drills do not work well and maybe these wil work better

http://www.rockler.com/product.cfm?page=30948

[longballlumber]

Doug,

In addition to the Braid Point bits that Jim suggested, I always try to clamp an extra piece of wood on the side where the bit will be exiting (splinter side). In theory you will be drilling into another piece of wood instand of plunging thru as the wood thins. Don't push too hard let the bit do the work!!!!

Later,
Ball

[sanyijr]

Doug,

In addition to the Braid Point bits that Jim suggested, I always try to clamp an extra piece of wood on the side where the bit will be exiting (splinter side). In theory you will be drilling into another piece of wood instand of plunging thru as the wood thins. Don't push too hard let the bit do the work!!!!

Later,
Ball

As Ball said. Always duble up the materal on the back end of drilling or cutting (saw) will prevent tearout and chipping. Just need some sacraficial wood scraps....

Sean

[DPeterson]

Thanks guy's. I forgot about the back plate procedure. Although it seems I have as much trouble on the face as I do the back.

I have some Braid points. Not sure why I have not tried them. I like the reamer idea. Seems to be safest way to drill.

There are a bunch of different reamer styles. Steve - do you use the tapered types or do you have an assortment of various sizes?

Doug

[properchopper]

Doug,

Having drilled lots of holes in fiberglass boats for custys, and worrying over the glass chipping, I always drill a small pilot hole, use tape, AND lube the bit and pilot hole with lightweight oil, then go really slow with minimal pressure. May not work that well on wood, but the lube keeps the chisel-points of the bit from grabbing and flinging off the gelcoat. You might also try a Unibit.

[dana]

not sure how to get the holes lined up by using this method, but when i want to make clean holes, i clamp a piece of straight hardwood where im driiling. then i drill straight thru the hardwwod and thru my piece. having the wood on top makes everything one solid piece so when you hit whatever youre drilling its not like starting it there. you can also prevent chip out when coming thru the backside of something youre drilling with this same method. i hope this doesnt sound too confusing )

[sundog]

Yep, Ive chipped my share of gelcoat. Now I use a cone shaped ceramic bit (like a Unibit) in my Dremel style tool to get through the fiberglass, then run a regular drill bit through to finish the hole.

[keithbradley]

Unibit + masking tape

[m4a1usr]

I gotta agree the back plate is most easily the simplest method. Fast and takes little effort. If you have a dedicated set of bits (only for wood or soft materials) you can do some bit magic by modifying the cutting edge and back cut surface area. Its known as a minimal ride cut. But you have to do it from experience. Your not going to learn it from a book or description. Its a learned technique and is what machinists develop when having limited inventory, yet are faced with varying work products.

In short its where the cutting face is higher or deeper cutting, depending on your perspective, then the load surface. If that doesnt make sense look at a drill bit from the cutting end. You see the flutes and the metal cutting edge. Then there is the rounded or ride surface (behind the cutting edge) that makes contact with the material being cut into. This is to minimize loading a bit. That surafce area is what needs to be reduced or the angular contact area reduced. With excessive pressure, you can force a drill into the material where it shears the drill due to the flutes not clearing cuttings and too thin or too small a diameter drill.

Having said all that, again it boils down to experience with material being cut and how you modified the tool. Its easy. Once you know what you are doing and the capability of your custom made tools.

John

[Alexgar]

i think higher speed with less pressure works better for me

[Diegoboy]

I start the bit normally, then run the bit in reverse the rest of the way through.