Drilling holes with very limited access

[Midpack]

I have a problem, and I am hoping for a better solution than the one I've come up with.

• I am starting with pic A. The fiberglass thickness and hole are about 1/2-5/8" for some scale.
• I am trying to drill a hole thru a piece of fiberglass channel (blue) that is bonded to another flat fiberglass surface (green). It was supposed to have a hole drilled as shown in pic D, but it was missed by the manufacturer.
• Space is very limited (I think a basic power drill at an angle will fit, but barely), and I can only drill from one direction (right to left in pic).
• The hole would have been constant OD/parallel (like pic D), but it does not have to be parallel to the green surface, as long as the bottom of the hole is (like pic C).
• The hole must be as close to the green surface as possible...
• ...but it's critical that I don't nick/drill into the green fiberglass while drilling through the blue.
• I am only drilling two holes, and the project is over.

I haven't found a 'zero clearance right angle drill' but I wouldn't want to buy one anyway, renting one would depend on cost & availability.

All I've come up with is drilling a pilot hole as shown in pic B. And buying a cone shaped bit to drill and enlarge the hole as shown in pic C. I would proceed cautiously, drilling and looking repeatedly (with flashlight), in the hope that would prevent me from nicking the green surface.

Any other cost effective ideas?

 

[ERD50]

Dimensions would help get some feel for what you are up against. And how much access is 'very limited' access? Are we talking 1/4" hole, or 2" hole or ? 6" access, 12" or ?

-ERD50

 

[omni550]

I have a problem, and I am hoping for a better solution than the one I've come up with.

• I am starting with pic A.
• I am trying to drill a hole thru a piece of fiberglass channel (blue) that is bonded to another flat fiberglass surface (green). It was supposed to have a hole drilled as shown in pic D, but it was missed by the manufacturer.
• Space is very limited, and I can only drill from one direction (right to left in pic).
• The hole would have been constant OD/parallel (like pic D), but it does not have to be parallel to the green surface, as long as the bottom of the hole is (like pic C).
• The hole must be as close to the green surface as possible...
• ...but it's critical that I don't nick/drill into the green fiberglass while drilling through the blue.
• I am only drilling two holes, and the project is over.

I haven't found a 'zero clearance right angle drill' but I wouldn't want to buy one anyway, renting one would depend on cost & availability.

All I've come up with is drilling a pilot hole as shown in pic B. And buying a cone shaped bit to drill and enlarge the hole as shown in pic C. I would proceed cautiously, drilling and looking repeatedly (with flashlight), in the hope that would prevent me from nicking the green surface.

Any other cost effective ideas?

Contact the manufacturer and explain that they skipped a step (hole drilling)....have them make it right.

omni

 

[Midpack]

Dimensions would help get some feel for what you are up against. And how much access is 'very limited' access? Are we talking 1/4" hole, or 2" hole or ? 6" access, 12" or ?

Added to the OP, thanks.

Contact the manufacturer and explain that they skipped a step (hole drilling)....have them make it right.

We've talked, and once I sent them pics, they agreed it was their mistake and they agreed to pay. But I want to make sure it's done right, and at reasonable cost. A third party is going to have to do the work, me or someone else.

 

[bjorn2bwild]

Sometimes there is no substitute for the correct tool.
If you can get the correct alignment with your current set-up i.e. the pilot drill/step drill, then you should be able to cut down (make shorter) a drill of the desired diameter to finish the job.

PS - there are right angle drill attachments like this one - http://www.toolbarn.com/milwaukee-4...rm=milwaukee-49-22-8510&utm_content=Milwaukee

 

[W2R]

Contact the manufacturer and explain that they skipped a step (hole drilling)....have them make it right.

omni

+1

Why should you have to buy a new drill bit or anything else, or spend any time or effort whatsoever doing this, when the problem is clearly due to a manufacturing error? You already paid for this to have been done properly for you.

 

[ERD50]

Sometimes there is no substitute for the correct tool.
If you can get the correct alignment with your current set-up i.e. the pilot drill/step drill, then you should be able to cut down (make shorter) a drill of the desired diameter to finish the job.

PS - there are right angle drill attachments like this one - Milwaukee 49-22-8510 Right Angle Drill Attachment | ToolBarn.com

Also, @ 1/2-5/8" D, you could get a short spade bit and/or cut it down in length.

-ERD50

 

[Midpack]

Sometimes there is no substitute for the correct tool.
If you can get the correct alignment with your current set-up i.e. the pilot drill/step drill, then you should be able to cut down (make shorter) a drill of the desired diameter to finish the job.

PS - there are right angle drill attachments like this one - Milwaukee 49-22-8510 Right Angle Drill Attachment | ToolBarn.com

I probably haven't descibed the problem well enough. The primary issue isn't bit length or right angle, it's drilling parallel to one surface as close to that surface as possible. e.g. with a conventional drill, the chuck prevents me from getting close enough and parallel.

 

[samclem]

Some thoughts:
1) Put some thin metal down on the green surface to protect it. "Skip happens" and there's a good chance that the bit, the chuck, or some other thing will make at least momentary contact with the green surface as you are doing the work.
2) If there's room, use long bits in order to provide the necessary clearance for the drill from the green surface.
3) A step-bit or a bit with a small pilot tip will help keep the bit from wandering as you start.
4) Do you really need a perfectly round hole? If not, I'd think about using a Dremel tool with a round file to "hog out" a hole just where you need it. It offers a lot more control, you can do things a little bit at a time to make sure you are removing just the right amount of material and not anything extra.
5) A right-angle chuck or even a flex adapter with a hex-end bit might give you the flexibility and clearance you need. The flex adapter is really meant for use with a screwdriver, but if you take it slow it ca be used for drilling small diameter holes.
6) If you can't find a cone bit, consider using a router bit of the correct angle to let you get close to the flat surface.
Flex adapter: $5 at Harbor Freight

 

[NW-Bound]

4) Do you really need a perfectly round hole? If not, I'd think about using a Dremel tool with a round file to "hog out" a hole just where you need it. It offers a lot more control, you can do things a little bit at a time to make sure you are removing just the right amount of material and not anything extra...

The above, and/or some hand filing?

 

[ArkTinkerer]

I probably haven't descibed the problem well enough. The primary issue isn't bit length or right angle, it's drilling parallel to one surface as close to that surface as possible. e.g. with a conventional drill, the chuck prevents me from getting close enough and parallel.

The answer to this is a longer bit. The further the drill is from the flat surface the lower the angle. The tool listed previously will reduce the required distance from the drill by reducing the chuck size. Also, you can get other chucks in different sizes.

I strongly second the idea of putting a thin sheet of metal down to protect the surface.

Also consider drilling an undersized hole and enlarging it with a Dremel or other hand grinder if the hole doesn't have to be perfectly round.

 

[Ronstar]

Simple job with a right angle drill and step bit or longer bit, depending on space constraints. That's what I use in situations like this and it works fine. May have to touch up the hole with a round file.

 

[bjorn2bwild]

the chuck prevents me from getting close enough and parallel.

This is the key. You need to remove the chuck from the equation to allow parallel alignment. With 1/2 to 5/8" diameter requirement, a hex-shank bit in a flex drive or extension as mentioned above should do it.

 

[Midpack]

1) Put some thin metal down on the green surface to protect it. "Skip happens" and there's a good chance that the bit, the chuck, or some other thing will make at least momentary contact with the green surface as you are doing the work.
2) If there's room, use long bits in order to provide the necessary clearance for the drill from the green surface.
3) A step-bit or a bit with a small pilot tip will help keep the bit from wandering as you start.
4) Do you really need a perfectly round hole? If not, I'd think about using a Dremel tool with a round file to "hog out" a hole just where you need it. It offers a lot more control, you can do things a little bit at a time to make sure you are removing just the right amount of material and not anything extra.

The answer to this is a longer bit. The further the drill is from the flat surface the lower the angle. The tool listed previously will reduce the required distance from the drill by reducing the chuck size. Also, you can get other chucks in different sizes.

I strongly second the idea of putting a thin sheet of metal down to protect the surface.

Also consider drilling an undersized hole and enlarging it with a Dremel or other hand grinder if the hole doesn't have to be perfectly round.

Simple job with a right angle drill and step bit or longer bit, depending on space constraints. That's what I use in situations like this and it works fine. May have to touch up the hole with a round file.

Thanks!

1. I had not thought about a longer bit, that would help. I used a smaller diameter 12" bit once and whip made it unusable in that situation, but larger diameter and lower rpm in this case might work.
2. I can protect the green on the entry side, but my big concern is the exit side where I can't protect or see.
3. The hole does not have to be round/constant diameter. As long as the bottom of the hole is parallel with the green surface. I am drilling into upside down channel, like a small tunnel.
4. I thought about a Dremel, but I assumed it wouldn't be powerful enough to bore through 1/2-5/8" of fiberglass. Will it? I don't have one, but I am sure I could borrow one.
5. I don't follow how a flex adapter would work for my situation?

 

[JoeWras]

Don't we have retired dentists on this thread? This looks like the kind of thing they do all the time. (On a smaller scale, of course.)

 

[Ronstar]

I have a smaller dremel and I think it would be tough. But one of their more powerful models may be able to handle it. Dremel would be ideal for tough access jobs like this if it has enough power.


Sent from my iPhone .using Early Retirement .//82339)

 

[ArkTinkerer]

I thought about a Dremel, but I assumed it wouldn't be powerful enough to bore through 1/2-5/8" of fiberglass. Will it? I don't have one, but I am sure I could borrow one.

A Dremel certainly will but if you want more power and to go faster a rotozip with a carbide burr will certainly do the job. Big question is can you control it? Slow with a Dremel is much easier to control if you really are worried about not grinding something you shouldn't. But to speed it up you can drill a smaller hole before you start grinding.

 

[ArkTinkerer]

Rotozip is also yet one more tool to own. That may be good or bad depending upon your point of view!

 

[pb4uski]

.....We've talked, and once I sent them pics, they agreed it was their mistake and they agreed to pay. But I want to make sure it's done right, and at reasonable cost. A third party is going to have to do the work, me or someone else.

Can the manufacturer send you a new part, unit or whatever? IOW, make it their problem to come up with the remedy. If you try doing it and mess it up then you'll have a bigger problem.

Otherwise, it seems the best approach is to protect the green surface with metal tape or something like that and use a long or flexible drill bit.

Are there machine shops nearby that the manufacturer could subcontract the project to? That way, if the shop messes it up the problem rests with them and the manufacturer and not you.

 

[Midpack]

Nothing can be removed or replaced.

May not mean anything to most, but it's two limber holes that weren't drilled in the large structural grid laminated to the inside of a boat hull under the floorboards. Prevents complete draining of the bilge.

Again, the manufacturer has been reasonable IMO, so I am willing to work with them.

But I've gotten a couple ideas worth follow up, thanks. I'll probably go with a long 1/2" bit or a cone/step bit, whichever is cheaper. I like the Dremel idea, but I assume even the better models aren't powerful enough for this task.

 

[MRG]

How about jewelers files for cleaup, instead of Dremel. Cheap, slow, accurate you just have to be patient and lots of time..

Sent from my SAMSUNG-SGH-I337 using Early Retirement Forum mobile app

 

[FireBug]

I love to spend other people's money, and if a round hole is required, this won't work. But it will keep you flush with the green plane and you can set the blade at a right angel.


http://www.amazon.com/Bosch-MX25EC-...d=1418679179&sr=8-10&keywords=Tools+vibrating

 

[Midpack]

How about jewelers files for cleaup, instead of Dremel. Cheap, slow, accurate you just have to be patient and lots of time..

I have some round files and I may use them for that last little bit to "lower the hole" if necessary, I gather that's what you're getting at. But the hole doesn't have to be pretty at all. Once I drill them out, I will coat the inside with a thin coat of epoxy to seal them (even though it's technically unnecessary), and if all goes well I will never see or think about them again.

 

[MRG]

That's exactly what I was trying to say. You got it. Best wishes.

Sent from my SAMSUNG-SGH-I337 using Early Retirement Forum mobile app

 

[bjorn2bwild]

One last thought worth mentioning - if aesthetics will allow, a number of smaller holes will drain the same amount of water as two large ones.