Enlarging bulkhead hole

[Doug]

Can you enlarge a 1 1/8th drilled hole to 1 3/4, so they can take a 1in bulkheads?

I cant even get a 3/4in bulkhead in there, as I planned on. Even that takes a 1 1/2 in or 1 7/16in. hole. Only other option is to go with 1/2in and then enlarge stacks to 1in. but still a 1/2 in drain. I would then have two 1/2in drains and a 1in main drain for my bean

[sphelps]

It can be done by drilling another hole around it but unlikely anyone would attempt it. Better just to work with what you have, I'd use the two 1/2" lines for the primary and secondary and the 1" as the back up. I'd also up the line size before and after the bulkhead to 1" like you mentioned, 1/2" bulkhead with 1" line will flow a decent amount, much more than 1/2" line throughout and not much less than a full 1".

[LoJack]

Definitely risky to drill around it. I would do it if it was a brand new bit, and I'd be the most patient man on the planet … but still no guarantee's

Can you fit any sort of plug into it? I have a tank that was drilled once and I didn't need to use a sump anymore, so I inserted plugs into the threaded bulkheads with teflon tape so that I could just use it as a regular tank.

If this is an option, I'd consider plugging those off and drilling new holes where you want them. Not ideal, but probably less risk of crackle/breakage going that way. Assuming the original bulkheads don't leak I suppose.

[monocus]

make yourself a jig for the new hole so your drill doesn't move around using 1/4 " plywood.be patient and go slowly.

[Doug]

Thanks for the great advice guys. I decided that if I need a new bit anyways, to order a 1.75 bit for a new 1in. bulkhead in the back. I also ordered a pair of 1/2 in. bulkheads for the two bottom holes. One will be brought up to a 1 in. stack and drain line as per Steves suggestion. The other to 3/4 in. for my return line.

Sounds good, as long as the second hole drilling goes good. At least this time I will be using a new bit.

[Evilweevil]

Just go to princess auto they drill fine and go with the plywood jig like mono us said go slow and don't use a lot of pressure it will drill fine