Cut worktop from top or bottom side

I've got a Worktop that I need to cut to size as well as the cut-outs for hob and sink. I was planning on using the Circular saw for the straight cuts and a combination of spade drill bits and a jigsaw for the cut-outs.

Should I be cutting on the finished side of the worktop or from the back?

Thanks in advance.

 

Whatever method of cutting you use, you need to make sure that the cutting teeth cut into the top finished face as opposed to breaking through from the inside out. That normally means cutting laminate worktop upside down and from the front moulded edge towards the back.

You do it that way to prevent the good face splintering or chipping as the cutting teeth rip through the unsupported surface.

 

also make sure both haves are fully supported[ minimum 2 full width supports each side] and level otherwise you can get the blade binding or splitting as you get to the back edge

 

Laminate? timber top?

 

It’s a laminate worktop.
Here’s a picture of my circular saw.


If I’ve understood the above correctly, I should cut the worktop from the underside. Whether I start from the rounded edge or the back edge shouldn’t matter?

here’s a picture of my jigsaw blade

I assume this also needs to be cut from the back side. Except, what’s stopping the jigsaw from piercing the laminate surface when it is on the downward motion?

Thanks for your help

 

you must cut front to back so the breakout is at the back
with a downcut jigsaw blade it cuts on the down stroke
just think "the tooth must cut through the finish into solid material "
otherwise when the tooth break the surface it lifts the finish that is now only as good its bonding with the surrounds

 

You say you have a jigsaw , personnaly I would drill hole in top and use the jigsaw for cut outs , there are jigsaw laminate blades which cut back to front , masking tape on the side of the board you want to use will help prevent any chipping .

https://www.screwfix.com/p/t101brf-...RI6VwfuBDuY50yyJCUxoC2AsQAvD_BwE&gclsrc=aw.ds

 

Looks like a course blade , one with more teeth would give finer cut.

 

Personally, I detest those down cut blades (T101BR and T101BRF) because on anything thicker than about 10mm they have a tendency to bend sideways in the cut and give you anything other than a perpendicular cut.

Before getting a plunge saw and rails I used to mark cut outs out on the top, drill my corners (normally using a sharp, slow running auger bit at 300 rpm or so - a hand brace and bit are also good), then make my straight cuts from the underside by plunging in to "join the dots" (holes) using a corded circular saw with a fine tooth blade (for a 165mm saw that would be something like 48t blade - a jigsaw with orbit set off and a finer blade such as T101B would also do the job and be far better than the T111C blade the OP has) and lastly from the top I'd finish the cuts into the holes using a relatively fine sharp hard point saw (say 20 or 22in at 9 or 10tpi), althougj this step isn't requiredcif using a jigsaw. The keys to success include using a freshly sharpened or new cutter/saw/blade and choosing fine tooth items

BTW OP, whilst that saw blade might be OK for ripping rough pine , it is nownhere near fine enough to tackle laminates. It also looks well used so is probably just a bit blunt

 

1. Practice on an off-cut first and see what works for you.

2. For sink and hob cutouts, generally the edge of the sink/hob covers the cut edge so the cut doesn’t have to be 100% perfect.

 

Thanks for all the suggestions. A few follow-ups please.

I still don't understand this, sorry. Given my circular saw and the way the blade spins, I can understand that I would need to use this from the underside of the worktop as this will then cut through the surface and avoid a breakout. I don't understand why I need to go from the front to the back when cutting the underside of the worktop. Can you please help me understand.

I have Bosch spade bits. Can I use this for my corners and drill from the top surface of the worktop. Once this is done, I can join the dots on the underside of the worktop and use my upward facing blades on a jigsaw?

I can also test this on an off cut of the worktop. Appreciate all your advice.

 

I have never used them. do they make the jigsaw bounce off the surface?

 

If you don't cut from front to back you may get breakout on the edge of the worktop when you cut the worktop to size. If you don't the blade will be pushing against the laminate on the edge as you push the saw forward. It doesn't apply to cut outs.

Out of interest, are you only cutting one length of worktop to fit a straight span or are you going to end up with an L shaped worktop. If the latter you need a router and worktop jig if you want to avoid having those metal strips between sections.

 

You cut into the front edge of the worktop for the same reason. You want the blade cutting into the good face, not ripping out of the front edge and potentially splintering it.

Standard jigsaw blades have upward facing teeth so yes, if you need to join drilled holes cut, cut the worktop with your jigsaw with the underside facing upwards.

 

Yes, and then some! Down cut blades take a firm hand (pressing downwards) to keep the base if the saw on the work piece