Dexter Posted July 29, 2012 Report Share Posted July 29, 2012 My 8 Foot has 2x 25mm bulk heads (which is no where near big enough) and I want to put 2 x 40mm(let know if that is is big enough) so I have a question. Is it a good idea to drill NEW BIGGER holes over the top of SMALLER HOLES? OR Is it better to blocked up the old ones and Drill Holes? Thanx in advice. Link to comment Share on other sites More sharing options...
cram Posted July 29, 2012 Report Share Posted July 29, 2012 drill over the existing holes. Link to comment Share on other sites More sharing options...
cichlidwife Posted July 29, 2012 Report Share Posted July 29, 2012 drill over the existing holes. just make sure you use a template, and make sure smaller hole is in the middle to be drilled, i think this was up a while ago and someone else asked the same question, there were pics also mike Link to comment Share on other sites More sharing options...
Dexter Posted July 29, 2012 Author Report Share Posted July 29, 2012 That is what I was hoping to hear. And I wont be drilling them myself I will be paying someone to do it. Also Is it posible/good idea to drain half of the water and leave Fish in there and drill the holes? Or will these stresa the Fish out too much? Link to comment Share on other sites More sharing options...
Craigo Posted July 29, 2012 Report Share Posted July 29, 2012 I have allways used the edge of the existing hole to start the cut for the bigger hole, just me but works. Juts follow the number 1 rule.... Don't be scared Link to comment Share on other sites More sharing options...
Dexter Posted July 29, 2012 Author Report Share Posted July 29, 2012 Juts follow the number 1 rule....Don't be scared Easier said then done....then again the tabk WAS free....but it wont be free to replace is something goes wrong.:s Link to comment Share on other sites More sharing options...
cram Posted July 29, 2012 Report Share Posted July 29, 2012 its seriously easy - especially with 10mm glass like mike says use a template (plywood etc) - run some water over it and use a cordless - just don't push too hard at the end or you'll get bits chipping off - most of this will be covered by the bulkhead though... Link to comment Share on other sites More sharing options...
guest 11 Posted July 29, 2012 Report Share Posted July 29, 2012 it can be done man i got these done on my 8ftr as i wasnt happy with the size of the existing holes. especially since i was told it couldnt be done buy a tank builder up the coast ere but there proof is in the pic Link to comment Share on other sites More sharing options...
ash Posted July 29, 2012 Report Share Posted July 29, 2012 Yes safe to do with fish in tank. I added two more 40mm bulkheads to my 8 footer and lowered the water enough to get the drill in there, didn't have access to back of tank as it was against a wall, was a lil to sketchy to do with electric drill so used a battery drill, if you do use a battery drill just make sure to not use an impact driver. Fish were fine. Link to comment Share on other sites More sharing options...
