Auburn02

My Feedback: (1)

What's your favorite technique for drilling a (fiberglass in this case) fuel tank for the vent and clunk fittings? Since the tank is sealed I can't get any masking tape on the back side obviously to deter splintering from the drill bit. Furthermore, the clunk hole will need to be somewhere in the neighborhood of 5/8". Would you drill a smaller hole (maybe 1/4") and then use a dremel to grind out to the full diameter? Unibit? Try to free hand it with a sharp #11 blade?

Next question, when adding a vent like this one (Hi-Flow Vent [TA-SR-1005] - $7.95 : ShopBVMJets.com, your one stop jet shop!) do you even use the hex nut? Try to put it on from the inside of the tank via the clunk hole, or just drill the hole and thread the fitting in from the top with or without the hex nut (using Hysol of course)?

Surprisingly couldn't find any existing threads, I'm sure they're out there but my search came up short.

JoeJr1485

I use a Step bit and once I get the whole size I want I then razor blade the edge.

marc s

Hi Permagrit do a range of carbide cone cutters, mark the hole on the tank, pre drill a pilot hole with a drill and then pop the cone in and open the hole out to the desired size.

Permagrit tools by the way are almost totally indestructible.

marcs

SECRET AGENT

My Feedback: (18)

I just use a dremel sanding drum or a carbide grinder. Make sure you clean the heck out of it with alcohol after you are done making your holes or else the dust and debris will clog the heck out of your UAT (ask me how I know, HA).

I never used the nut on the backside of those vents, just glued them with Hysol.

Len Todd

I just did this for a vent fitting. Per the manufacturer's rep, drill out the hole one size smaller, screw it in and hysol it in w/o the nut. I did clean the hole up with the razor knife and sanded the fitting and tank a little where the glue was going to contact it. The clunk fitting was already installed in my tank. So I can't help you there.

Auburn02

My Feedback: (1)

Perfect, thanks guys. Shouldn't be a problem, just wanted to have some collective ideas.

BarracudaHockey

My Feedback: (11)

I wish we would have more threads like this, I always learn new ideas to solve problems.

ChuckC

My Feedback: (24)

Getting a nut on the backside: there's a trick using a fine, stiff wire (or string) that you thread through the barb, then into the tank and out the large bung opening that at least allows you to get the nut aligned to the threaded side of the barb. Similar to what you do when re-plumbing a gas weed eater. Some of those re-build kits even come with the wire. Next, you have to be able to get either a wrench or curved hemostats onto the nut. Simple in theory, almost impossible in practice with many tanks...

Still need Hysol after...