Drilling Through An Exterior Wall - What Type of Bit?

[TucsonJim]

Thanks Rob. It's certainly worth a try.

Jim

[Scott'n'Wendy]

I have several. Dia ranging from 1/2" to 1 3/4". No pilot hole required. They start out drilling a1/8" hole then "step it up" a 1/16 or 1/8" at a time. Depending on the bit. But...... they are not cheap
https://www.harborfreight.com/2-piec...YaAkDZEALw_wcB

The ones I have are greenlee. I see HF has some

[COReflection]

I'm going to drill a one inch hole through an exterior wall to install a data port. What would be the best bit to use? A hole saw? A spade bit? Other?

Thanks,

Jim

If you're just drilling through the wood and fiberglass and want the cleanest hole----use a Forstner Bit. They make the cleanest holes and I use them allot for furniture and carpentry. You can get a set of them or the specific size you need. The good ones are super sharp and they cut like butter. No rocking or jagged edges on either side of the hole like a hole saw can leave. No need for a pilot hole either---they will not walk. I would definitely not use a spade bit.

[howson]

TucsonJim

From my dryer install notes. This post is not to counter any of the other suggestions or methods, just what worked for me.

[ncitro]

COReflection I would not recommend a Forstner bit for this. With the foam in the middle, without the center pilot but to puncture the wood on the other side I don't think there'd be anything to keep the but straight when going through the middle layer. It might work but I would not trust it. I use them in woodworking as well and love them, just not sure about the foam.

[Cate&Rob]

Agreed that a Forstner bit is great for wood . . . But I also do not think it will work very well for the styrofoam core of the wall.

Rob

[COReflection]

Agreed that a Forstner bit is great for wood . . . But I also do not think it will work very well for the styrofoam core of the wall.

Rob

Good points but I am still wondering...since the foam is quite stiff and dense if it would work going slowly to mark and scribe it. I'm seeing others using those bits also drilling through 2" foam insulation in walls and recommending them but I get what you are saying. If we could only test our theories.....on a piece of sample trailer wall....Lol

[Scott'n'Wendy]

.....on a piece of sample trailer wall....Lol

That would be handy

[Scott'n'Wendy]

howson
Looks good Howard

[Canyonlight]

Jlawles2

Agreed that rocking or rotating the drill as you describe is important, particularly with larger diameter hole saws. I have had good luck running the saw backwards to prevent surface chipping with Formica and fibreglass (boat hulls). Once through the surface, the saw can be switched to forward for faster cooler cutting of the core material.

Rob

Rob - seems as I recall you also suggested (and you did) covering the area to be drilled using some sort of tape to help prevent any chipping and that worked well for you on your counter top. Not certain if this chipping of the exterior gel or interior luan is a concern for you Jim TucsonJim or if this will even be effective.

Dan

[ncitro]

Good points but I am still wondering...since the foam is quite stiff and dense if it would work going slowly to mark and scribe it. I'm seeing others using those bits also drilling through 2" foam insulation in walls and recommending them but I get what you are saying. If we could only test our theories.....on a piece of sample trailer wall....Lol

Unfortunately the walls are not rigid foam insulation like you see in home construction. Think more the white foam they make cheap coolers out of. I think if you hit it with that bit it would just tear and shred it.

[Canyonlight]

Jim TucsonJim - another consideration would be to contact Steve huntr70 for any feedback if interested and Steve does not check in. I suspect the dealership has drilled many holes into RV walls for certainly dryer vent installations but I suspect other reasons as well.

Dan

[Lonestar]

Good points but I am still wondering...since the foam is quite stiff and dense if it would work going slowly to mark and scribe it. I'm seeing others using those bits also drilling through 2" foam insulation in walls and recommending them but I get what you are saying. If we could only test our theories.....on a piece of sample trailer wall....Lol

Lots of good ideas in this thread, but as far as preventing splintering on the outside surface I'm thinking the Forstner bit is least likely to create a problem. What about a very small pilot hole all the way from the outside to the inside. Use the Forstner bit to cut the hole in the outside wall, and even in the inside wall (though other bits could be used here if needed), and then drill through the foam with a hole saw, or just clean out the foam with any cutting tool.