How to cut two 2 1/4" holes in vinyl soffit?

[trader4]

I need to cut two 2 1/4" holes in a vinyl vent type soffit. The holes will be next to each other for 2" PVC pipe to run through. The soffit vent material is not flat. It's flat for a few inches then has about a 1/2 dip, then flat again, etc. Any ideas on how to proceed? It's at the top of the second story too, so access is only from a ladder. Best thing I could come up with so far is a hole saw? Also, I figure the back up plan if I screw up the holes is to cut a square opening with a key hole saw and then find a piece of the same vinyl soffit, cut the holes in that piece on the ground, then glue it over the cut opening.

Any other ideas?

[jamesgangnc]

If you make sure your center bit is long enough you can do this with a hole saw. It's going to want to grab bad when the saw part hits the material. Since it's plastic you can run the drill in reverse and that will lessen the grabbing. You still want a good grip on the drill. If you have scrap it wouldn't be a bad idea to try it there first.

[dpb]

Hole saw work fine for the vinyl; question is what's behind it or is it all there is at that point? If'en there's anything nearby to tack it to, I'd predrill the holes in a piece of 3/8 or 1/2 ply and use it as guide to avoid possibility of the holesaw grabbing an edge and yanking me while I'm on the ladder.

Depending on the particular vinyl, some is quite easily cut w/ sharp utility knife. And, of course, if you happen to have it in the kit, the Greenlee punch works as well as for sheet metal (altho it's mighty pricey if you don't have :) )...

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[Colbyt]

Cordless drill, low speed and the hole saw. Go slow and use light pressure. Spin out in your center hole or pushing too hard are your greatest perils.

Every other "dip" on the soffit has the locking channel which will be much harder to cut then if you are in the center of a single board. If possible avoid that.

[trader4]

Nothing behind it but air. Which I guess is good, because there is nothing else to drill through. But it's bad because the thin plastic is gonna want to bend and get away from the hole saw.

The grabbing was my concern too. Nothing to easily tack onto for a guide either.

No punches. And the punch would need access from behind too, no? I can't get my hand in there from the attic, though there is room for the pipe to pass.

I also like the other suggestion to use a cordless drill with good speed control to try to lessen the grabbing.

[jamesgangnc]

As I said once before, reverse the drill. A holesaw will cut plastic when run backwards.

[JoeSpareBedroom]

As I said once before, reverse the drill. A holesaw will cut plastic when run backwards.

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Two votes for that idea. A hole saw run in reverse will even cut soft materials like car door panel fabric or vinyl. It should do fine with the plastic he's dealing with.

[Pete C.]

Second this, I had the same idea. A guide template of plywood will keep the hole saw on track, even if it looses it's center pilot. A piece of ply long enough to span two rafters/joists should allow you to secure it with a couple screws.

The punches also require access to both sides of the material. Someone would be needed in the attic to reach the pilot hole and screw the punch onto the drive stud.

[RickH]

A fine tooth hole saw or a hole saw made for tile wont knock you off the ladder if it kicks.

[WW]

Find a food can that is 2 1/4 inch diameter. Cut out the top. Heat with propane torch. the upper edge. Press against the soffit and melt through the plastic. Leaves a smooth edge. WW

[JoeSpareBedroom]

A Dremel tool would do the trick. Variable speed would be a good idea to keep from melting the plastic. That can clog the cutting bit, or fling hot goo onto your skin. It's got a way of landing only where your goggles do NOT provide coverage.

[trader4]

That's an interesting possibility and worth a try. If it works, it would be very simple. I think what I need to do next regardless of the approach is find a piece of similar or identical soffit material so I can do some experimenting.

Thanks for the idea.

[JoeSpareBedroom]

That's an interesting possibility and worth a try. If it works, it would be very simple. I think what I need to do next regardless of the approach is find a piece of similar or identical soffit material so I can do some experimenting.

Thanks for the idea.

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What's your co-pay for an emergency room visit? Do you need your hands to do your job?

[trader4]

What exactly is so dangerous about heating up the end of a tin can or similar and using it to cut cut through the soffit as opposed to any other method, eg hole saw? You have heard of gloves, haven't you?

[JoeSpareBedroom]

What exactly is so dangerous about heating up the end of a tin can or similar and using it to cut cut through the soffit as opposed to any other method, eg hole saw? You have heard of gloves, haven't you?

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Pish posh. It's a silly idea. Buy a Dremel tool if you don't have one. Everyone should. Their web site's got a guide to which bits would work best for your job. Home Despot or Lowe's both carry the bits.

[trader4]

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I have a Dremel and I don't see it as being a good solution. How can one control the pattern so that you get a round hole? Remember, this is 20 ft up in the air, on a soffit. With a hole saw, you have the center arbor that will help keep it in place.

Besides calling the idea to use a heated tin can or similar "silly", and offering "pish posh", whatever that means, I have yet to hear you explain what exactly is wrong with it and why it could not work?

[JoeSpareBedroom]

I have a Dremel and I don't see it as being a good solution. How can one control the pattern so that you get a round hole? Remember, this is 20 ft up in the air, on a soffit. With a hole saw, you have the center arbor that will help keep it in place.

Besides calling the idea to use a heated tin can or similar "silly", and offering "pish posh", whatever that means, I have yet to hear you explain what exactly is wrong with it and why it could not work?

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When you get the can hot enough, for long enough to do the job, it'll obviously be unsafe to handle. And yes, I've heard of gloves. Got any ancient asbestos gloves? No? Fugettabout this idea.

The hole saw's a great idea, but if you have any concerns about it grabbing the plastic and messing up the job, a more precise method is called for. Granted, running the hole saw backwards will help prevent grabbing, but it sounds like you're not comfortable yet with the tool.

The Dremel would be easy to control. I used to do custom car audio installations and I've used a Dremel to cut literally hundred of dashboards, while working in positions which were as tricky as standing on a ladder.

[jamesgangnc]

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You must admit though, keeping a dremel or a rotozip from wandering off is an aquired skill. Without lots of practice it';s hard to cut a nice round hole free hand.

[JoeSpareBedroom]

You must admit though, keeping a dremel or a rotozip from wandering off is an aquired skill. Without lots of practice it';s hard to cut a nice round hole free hand.

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No matter what he uses, he'll have to caulk around the pipe. Whatever.

[trader4]

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The plan was to get a reasonably round hole with no caulking required. It's a vented soffit so some gap is acceptable.