how to drill a hole on the 12' alum boat ?

[sparkes3]

go to a boat shop buy a plug insert have it welded in then buy a plug put it in and way to go.i just put new wood in the back of my 12' aluminum covered the whole back inside and outside then bought a plug drilled the hole to fit and bang i got a removable plug take it out when im home so it dont fill with water. and when its running i pop it out to drain while im duck hunting.

[tuchodi]

Steveston Marine have a kit which has an Aluminum sleeve with the correct rubber expandable plug. It is ment to weld it in but you can buy Liquid Aluminum and glue it in.

[x-hare]

You will find a THRU HULL Fitting at most Marine shops they are 3 pieces top and bottom with plug they will sandwich between the boat hull and is threaded use a marine sealant approved for use below waterline ( SIKAFLEX ) and your good to go.
Mount it as close to the stern as you can with good access the idea being when your under power you can pull the plug and drain the water.
Keep the plug on a string as not to lose it.
OH and NO WELDING NECESSARY

[city hunter]

I got it what I should do now,thank all of yours info,thanks again !!

[sparkes3]

x hare thats the one but i was to cheap /lazy to go get it

[870]

You will find a THRU HULL Fitting at most Marine shops they are 3 pieces top and bottom with plug they will sandwich between the boat hull and is threaded use a marine sealant approved for use below waterline ( SIKAFLEX ) and your good to go.
Mount it as close to the stern as you can with good access the idea being when your under power you can pull the plug and drain the water.
Keep the plug on a string as not to lose it.
OH and NO WELDING NECESSARY

yep.
mount as low as possible, so you can drain it on the fly.