Bigger Thru-hull hole

[tjelle1946]

Chris--mark an X across the opening large enough to use later. Fill the old hole with fiberglass or something other that will set up. Pre drill small hole in center and then do the new hole. It is more work but very accurate. jorgen

 

[chris20636]

I've fairly certain that I will be replacing the original 3/8 inch
thru-hull, used for engine cooling, with a 3/4 inch one, assuming
there is space at the current spot for the bigger hole and valve.
Having a hole already there complicates the cutting chore. The hole
cutting instruments that I have seen use a drill bit in the center to
keep the cutting tool centered. The best idea I have come up with is
to glue a plywood disk across the current hole that is slightly
smaller than the hole I am cutting. This would give the cutting tool
a surface to use for centering. Any other ideas/comments?

Thanks,
Chris
V-2933

 

[stevebirch2002]

Hi Chris

When we insytall a Beta the thru-hole is increased to 3/4 inch quite easily with a rough round file - ten minutes work and easy to do.

Steve Birch