cutting opening for undermonunt kitchen sink

[Darren]

Hi there, I'm going to be installing a undermount kitchen sink in a ************ countertop. Does anyone know the best approach re cutting with a jig saw and following up with a straight rounter; or do I want to make a plywood templete and cut the entire opening with a router. Any advise is appreciated.

Darren

[master plumber mark]

use a jig saw, and make a template first
mark the top where you eed to cut it,
I suggest that you outline where you are cutting
with grey duct tape to keep the line striaght ans also
protect your top

[jadnashua]

Because a jig saw blade can wander (a lot!) make sure you leave a good margin. IT could look great on the top, but the blade could bend in the cut and be way off on the back side. Once you get the main slabe cut out, then, use a template with a bearing on the router to follow the template to clean up the cut (a down-cut spiral bit might work best). Since the thickness is likely high, to keep the bit from chattering, it may be best to use several bearings to gradually take it down to the exact size. Trying to keep the wood looking good with the moisture around the sink might be tough. Good luck.

[breplum]

I only have 30 years experience in the trades but, in my humble opinion you should NOT use a jig saw unless the top is 3/4" or less and you don't care how it looks.
I would first recommend you have a countertop shop do this for you. But, if you must do it: Use a circular saw with a very high quality smooth cutting blade for the runs, cut from the back side and use clamped or screwed guides. Only use a jig saw to connect at the corners.
And fergodsakes, this is a plumbing site not countertop carpentry.

Wood and water do not do well over time and I have personally replaced a dozen sinks for customers who didn't like the deterioration after a few years.

[toolaholic]

my son and i have a welding and woodworking shop. soo we would use our largest [3 hp] router guided by a ply. temp.

not everyone has our recources. do the best you can with what you have.

if you use a jig saw, use long blade and go slow, it will want to wander.

use 2 blades! after 1/2 way put in another new [course tooth] blade.
good luck