How to Drill Parallel Holes ?

[hellosailor]

I'd also suggest buying a cheap piece of 2x3 or 2x4, and drilling some practice holes in it. Gives your hands and eyes a chance to get the "feel" for parallel, no matter how you are doing it, on something that should cost less about two bucks.

[MarkJ]

Originally Posted by ShipShape

HOW does one drill parallel holes? I can't even do it when the backing plate has two holes. And everything curving and sloping doesn't exactly help.

I have no mechanical aptitude at all but I can simply solve this problem: I would drill the first hole and then drink 14 beers and drill the second hole. Chances are as good as any they would be parallel.



But if it was on my boat I would pay some person to do it, but withold the cash till the jobs satisfactory completion.

[Blue Stocking]

Insert plastic drinking straws thru both plates and the cabin top in their assembled relationships. Wrap a little plumbers putty around the straws where they pass thru the backing plate, and jam it up against the overhead, secured by duct tape and a prop.
Lift the exterior plate to allow you to access the oversize hole, and hypodermic in some thickened epoxy. Support the exterior plate with wedges and duct tape.
Did this nto 104 holes in Bluestocking's deck. No leaks in 12 yrs

[zeehag]

i like bluestockings idea.
i usually have someone else do it so it comes out right.

[wannago]

Ex-Calif Moderator Person's thingy will give you three holes very perpendicular to the surface. if the surface is not flat, they will not be parallel.

(and, if you're mounting hardware to it, it's probably better if it is flat)

I've seen them for sale in Home Depot.

[ShipShape]

I got the drill guide today. The design is very cool - several useful features you probably won't notice just by looking at it. Unfortunately the quality is typical CCC (Cheap Chinese Crap), but it will do the job. Like Dan says, a picture is worth a 1000 words - here it is, and my plan on how to use it:





I'll use the backing plates as templates, and set them on a piece of plywood so that the holes go through the deck parallel. Here I shimmed the plywood with epoxy mixing sticks to keep it from rocking on the deck. I also used sticks to shim the base of the drill guide to compensate for the thickness of the backing plate.

When I am ready to start putting the hardware back, I'll pre-drill the first hole through the plywood so I can peer down the hole and make sure it is centered over the epoxy plug. Then when the first hole is drilled through the deck I'll run a bolt through everything so the plywood can't move when the drill cord drags under it, or or or. You know how things go wrong.

I can also use the drill guide to make a little jig when I need to drill holes closer to something than the base of the drill guide allows.
I'm not going to pre-cast holes any more using straws or wax-covered bolts - not only is it a hassle, the surface of epoxy gets that waxy bloom when it cures and I'm not so sure that sealant sticks to the wax as well as a fresh cut surface.

I'm waiting for some back-ordered bronze bolts for another part of this project before I can start re-mounting hardware. When I get going, if something interesting comes up I'll post it.

Thanks to everybody for your comments and input.

[steve_hendry]

one more tool:
Buy Drill Guide at Woodcraft.com

you might be able to adapt it to curved surfaces. I've been using one for installing ports, but the cabin sides are pretty flat.

[stevensc]

It is very difficult to do on a curved surface what I do is drill the holes as best I can then mark and drill the backing plate. if you want to use a premade backing plate maybe drilling it's holes out to a larger size and using flat washers under the nuts will work for you.
Steve

[SkiprJohn]

Shipshape,
Sounds like your system is going to work just fine.
regards,

[Boracay]

It may be possible to drill some of the holes from underneath the deck, through the backing plates.

You might need something like this:- Bosch 1132VSR

[PAR]

On the wooden dill guide I mentioned previously, if you set a fine thread machine screw (flathead), one each in the four corners on the under side, also perpendicular to the bottom (drill press again), you can use these to elevate the block, cant, incline, fit over stuff like seams, texture, etc., as well as concave, convex and compound curve surfaces. This is a simple tool, you make it once and use it repeatedly until you lose it or screw it up, then you make another. 30 seconds with a chop saw, a few minutes with a drill press and you'll get lots of service from it.

[Ex-Calif]

PARs tool is a great one. However it works for 1 drill size. You can make multiple holes in the base or just 1 hole and lay something like this on top of it.

[ShipShape]

PAR - that is a brilliant idea! And it works vertically as well as horizontally. I would (will) use oval or cap-head screws though - they will balance better on an uneven surface. And I've got a neat little level with a rotating bubble so I can match the angle of surfaces ... ooh Baby, that little tool can go places.

Ex-Calif Moderator Person - that is a nice little device but it has some problems: it doesn't look thick enough to easily guide the drill bit straight, it costs money, it's gonna rust, and it won't float when it falls overboard.

You didn't post the name of it either so that cancels out the $956.02 from your bill. California is a good place to be from though, so we can keep the $1 for your pretzels and the $3 for your beer.