How do I make holes in a fiberglass jetted tub to install deck faucet?

[Kevin Warnock]

I am putting in an American Standard brand jetted tub. This tub has a wide deck area that looks like a good place to install the roman deck mounted faucet. This would be unusual in a house, but I am trying to save space, and putting the faucet on the tub surface will help in my quest to make this tub fit. The tub appears to be made of fiberglass. I've seen shower stalls for sale at Home Depot that look like they are made of the same material, which is kind of stringy and abrasive on the side you don't see when installed. How does one make holes in this material? I am scared to just try my hole saw because I don't want to crack or destroy my new tub. The shower stalls at Home Depot don't have faucet holes pre-drilled, so I'm sure there is a safe way to make these holes, but I don't know what it is. Does anyone here know?

Thanks very much

[Jeremy]

Don't worry, fibreglass won't crack when drilling a hole as a ceramic tub might. There might be some chipping of the gelcoat around the hole, but this would probably be covered by the flange of the tap you are installing - but if not simply cut the hole undersize and use a file to enlarge it. Fibreglass is a very abrasive material and will blunt HSS sawblades quite quickly, so rather than potentially ruining one of your holesaws you may want to make the hole by drilling a 'chain' of small holes with a twist drill, knocking the centre out and filing it to the correct shape.

Lastly, the fibreglass in area you are planning to install the tap might be quite thin if the manufacturer didn't intend you to install a tap there - if this is the case then it will probably flex in use and possibly crack the gelcoat etc - if might be worth laminating more fibreglass on the the back to strengthen and stiffen the area up if it looks marginal.

Jeremy

[Utahclaimjumper]

A normal hole saw wil do the job, just keep the speed down on your drill.>>>Dan

[zubzub]

to really control a hole saw you can make a jig by drilling through a 3'4" piece of hardwood then clamp the wood the to the surface.  This will stop the hole saw wandering if the pilot hole is in soft material or if you need to reposition the hole a bit.

[JackConrad]

I did something similar to ZubZub. Only, I used the "plug" that it made by drilling a hole in a scap of oak with my hole saw. Becasue of the location I wanted the hole, I was not able to use any clamps. I screwed the "plug" to the shower, put the hole saw over the "plug" and drilled the hole in the shower.  Jack

[BG6]

Fibreglass is a very abrasive material and will blunt HSS sawblades quite quickly, so rather than potentially ruining one of your holesaws you may want to make the hole by drilling a 'chain' of small holes with a twist drill, knocking the centre out and filing it to the correct shape.

I'm going to disagree with you here.

A hole saw blade is pretty cheap, and IF TAKEN SLOWLY will make a beautiful, round hole in that tub in about 30 seconds.  The way you are suggesting is likely to lead to an oval hole, after a lot more time and effort.

This is probably why the professional installers that I've talked to use hole saws.

[Jeremy]

It's a fact that fibreglass will blunt HSS blades, which is why boatbuilders and other professionals that work with fibreglass use silicon carbide blades - whether that's an issue for an individual doing a small job such as this is of course down to them. I agree that holesaws are cheap enough to replace, although the ones I own came as a set which complicates things.

I personally would use the method I suggested (without any oval holes!) but others can of course use whatever tools or technique they wish.

Jeremy

[zubzub]

I did something similar to ZubZub. Only, I used the "plug" that it made by drilling a hole in a scap of oak with my hole saw. Becasue of the location I wanted the hole, I was not able to use any clamps. I screwed the "plug" to the shower, put the hole saw over the "plug" and drilled the hole in the shower.  Jack

good twist on an old trick.

[belfert]

I know from experience both in my bus and in my house that even four or five holes drilled in fiberglass with a regular old hole saw from Menards won't competely kill the hole saw.

Hole saws are inexpensive enough that even if it was dead after drilling the two or three holes it shouldn't be a big deal.

[bevans6]

I replace the pilot drill in the hole saw with 1/4" drill rod, then drill a 1/4" pilot first to locate the center of the hole.  This eliminates any tendency of the hole saw to wander from the 1/4" pilot drill wallowing out the pilot hole.  The drill rod is smooth so it just rides in the pilot hole, while the sharp flutes of the pilot drill can walk the hole sideways.

Just a bit of a tip.

Brian

[Airbag]

I replace the pilot drill in the hole saw with 1/4" drill rod, then drill a 1/4" pilot first to locate the center of the hole.  This eliminates any tendency of the hole saw to wander from the 1/4" pilot drill wallowing out the pilot hole.  The drill rod is smooth so it just rides in the pilot hole, while the sharp flutes of the pilot drill can walk the hole sideways.

Just a bit of a tip.

Brian

Brian most hole saws that come with a drill bit in them have what they call a gun drill meaning the flutes will not cut enlarging the hole.

[kyle4501]

I haven't had any problems using hole saws in fiberglass. But, I'm not on a production schedule & can run the speed slow & not build up heat. I'm also not drilling that many holes either. My Milwaukee 1/2" magnum hole shooter is my drill of choice for the smaller holes & a right angle drill is used for the larger diameter hole saws.

Another trick is to drill a 1/4" hole at each quadrant of the circle you are cutting out. These 4 holes allow the chips a place to go & the saw runs cooler & the plug falls out of the saw when you're done. 

I've had great success with the white painted Lennox brand of hole saws sold at Lowes. Once I bought the adapter, the saws aren't so bad. I'm building my hole saw set one project at a time.