5" flue, what core size?

[Dan Masey]

I have to fit a 5"horizontal vaillant flue today and wondered what size core bit to use. I normally use a 127mm for a 4" flue to give me the fall back to the boiler. But a 127mm might be a little tight. Any thoughts?

 

[AWheating]

a 6" core bit.

 

[mutley racers]

so you just drill out straight and not at an angle then?

 

[AWheating]

i drill straight when i use a 5" bit for a 4" flue.

well i try to.

 

[Dan Masey]

I've drilled at a slight angle with a 117mm core bit for a 4" flue. Normally strait with a 127mm core.

 

[plumber0808]

Drill Straight out for me, more accurate than drilling at a angle.

 

[vern]

a 6" core bit.

Yep 6"' done a few on BF fires of all things, you can hire the core cheap for the day as not worth buying for the odd occasions...

 

[Dan Masey]

Yep the core is around £90-100 for a 6" bit. Iv never had to use one in 10 years. Don't want to pay that. Ill hire one.

 

[AWheating]

if you know any sparks they may have one for kitchen extract fans you can borrow. Saves buying or the hire of one for one hole.

 

[supper plumb]

Defo use a 6" core there couple of used one going on ebay at the mot you mite be able to bag one for a good price!!! id rather buy a used one and have it for next time then hire one and get your pants palled down