enlarging a hole

marinelife · Jul 4, 2018

What is the best way to enlarge a hole for a bulkhead? right now I have a 1.5" bulkhead in my sump and need to go up to a 2" for a new return pump. Is this possible to do? it's an acrylic sump.

Luno · Jul 4, 2018

Leave the hole and you can buy fittings to step up or step down the plumbing itself. Much easier solution

Matthew Frost · Jul 4, 2018

Yes, and it's not hard to do. Get the hole saw you plan to use and drill a hole through a piece of plywood or scrap you have. Take that "pilot/template" and clamp it over the hole you are trying to enlarge and drill. Be careful to make sure the hole saw stays clean and free of acrylic debris as it will over heat and melt the acrylic. Just take your time and keep the hole saw teeth clean.

marinelife · Jul 4, 2018

Matthew Frost said:
Yes, and it's not hard to do. Get the hole saw you plan to use and drill a hole through a piece of plywood or scrap you have. Take that "pilot/template" and clamp it over the hole you are trying to enlarge and drill. Be careful to make sure the hole saw stays clean and free of acrylic debris as it will over heat and melt the acrylic. Just take your time and keep the hole saw teeth clean.

Thanks this is how I thought about doing it. Was not sure if it would work. The videos I watched did it with doors and other wood projects.

marinelife · Jul 4, 2018

Luno said:
Leave the hole and you can buy fittings to step up or step down the plumbing itself. Much easier solution

I thought about this but did not want to restrict the input of the pump.

Oldsalt01 · Jul 4, 2018

Matthew Frost said:
Yes, and it's not hard to do. Get the hole saw you plan to use and drill a hole through a piece of plywood or scrap you have. Take that "pilot/template" and clamp it over the hole you are trying to enlarge and drill. Be careful to make sure the hole saw stays clean and free of acrylic debris as it will over heat and melt the acrylic. Just take your time and keep the hole saw teeth clean.

Great idea for the "pilot/template". If you run the drill backward for a few revolutions with medium pressure, it will score the acrylic and reduce the odds of chipping or cracking. Take your time with this. Let the hole saw do the work and def keep the teeth clean.