Countertop cutout fail and how to correct it?

[ukworkshipper]

Hey folks,

I hope someone can spare some advice, I am really disappointed by these cuts I have made on a kitchen counter top. I have been doing woodwork for a few months and can usually get pretty straight and precise cuts with my jig and circular saws. This is the first time I have made this type of cut inside a countertop. It's a solid wood oak counter top, 40mm thick, and this was a rectangular cutout for a stove.

I drilled a whole in each of the four corners and then used a Bosch 130 jigsaw with a T308B blade, initially I didn't use the pendulum but I noticed it was taking very long so I set the pendulum to 2. I had the impression that the jigsaw was pushing me towards the inside. Once I was done I realized that almost none of my cuts were at 90°.

Pictures of shame

What did I do wrong? Is it something wrong with my jigsaw?

Is there a way I can partially correct this? Should I do a pass with my circular saw to straighten this mess or again with the jigsaw?

Any advice is greatly appreciated, especially as I will have to make a cut for the kitchen sink and then cut the corners of another counter top.

 

[John Brown]

Router. In my limited experience you'll never get a finish cut with a jigsaw. You can cut near the line with a jigsaw, but a bug powerful router is needed for the final cut.

 

[Bingy man]

Could be your blade choice , your jig saw under powered, your feed rate to high , blade blunt , ……… the thing to check is will the ( I assume hob ) fit into your cut out and overlap the edges and that the retaining clips can engage the worktop edges .. as for further cuts I’d definitely do a trial cut on an off cut before you cut the actual aperture. If you can still get them I use Bosch progresser blades with down cutting teeth ..

 

[Spectric]

Router unless you have a Mafell P1CC jig saw. Even a small router would do the job providing you went round taking small cuts each time but a big one would make easy work of it in far less passes.

 

[ukworkshipper]

Could be your blade choice , your jig saw under powered, your feed rate to high , blade blunt , ……… the thing to check is will the ( I assume hob ) fit into your cut out and overlap the edges and that the retaining clips can engage the worktop edges .. as for further cuts I’d definitely do a trial cut on an off cut before you cut the actual aperture. If you can still get them I use Bosch progresser blades with down cutting teeth ..

thanks for the reply, the blade is new and according to the Bosch documentation should be adapt to the job, I tried both at speed 5 and 6, is that too fast for this kind of job?

What do you mean under powered jigsaw? I thought the GST 130 was top of the line...

 

[ukworkshipper]

Thanks guys for the quick replies. Unfortunately I don't have a router. The hob fits snugly but it would be better to add those missing mm for better ventilation, that's why I want to get a clear cut.
Unfortunately I don't have a router and have to finish this job with the tools I have.

I have already cut this worktop on its end with my circular saw and got a pretty clean and vertical cut, maybe I should try the circular saw instead and finish the corners with the jigsaw. I have seen many video of people using a jigsaw for this kind of cut, even the instructions that came with the counter top suggest using a jig saw. So maybe I am doing something wrong.

 

[Cabinetman]

I’m sure it’s the first thing you checked but is the base set at 90degrees to the blade?

 

[TRITON]

Unfortunately I don't have a router

Which is a perfectly acceptable reason for going off and buying one. A small trim router like the Makita RTO702 will do the job as the base is small and that can prove handy when like this the workpiece is still in situ
It is currently on sale at Screwfix with 20% off so only £99
https://www.screwfix.com/p/makita-r...VUpJQBh0R4hlSEAQYASABEgLm7fD_BwE&gclsrc=aw.ds

Jigsaws are good for cutting curves and across the grain, but with the grain they are notorious for trying to follow it and making the cut anything but a straight 90 degrees.


It is not really to do with forcing the cut, or whether the blade is sharp out the packet or blunt as a butter knife, or even the power of the machine.
Pendulum action can help, but its really that the blade is flexible that the problems stems from.

I'd use a router to try to clean up the cut and take the off 90d bits away, but given those are going to be hidden by the appliance, theres no need to do a 100% job.

A bad workman blames the tools
A good workman blames the timber
The best workman blames both

 

[MikeJhn]

I am in need of some wooden worktop off cuts, if I knew where "heals" was I may be able to help, but heals just directs me to the department store.

 

[ChaiLatte]

...I use Bosch progresser blades with down cutting teeth...

Please could you provide some explanation as to why these would be a good blades for this particular circumstance. "I use" is unconvincing without surrounding logic to bolster the choice.

Please address the following matters:

A downcut blade is in compression on the cutting stroke meaning it is more likely to deflect at the free end of the blade. That would seem to exacerbate the problem that is described above, not reduce it. Think about trying to push a rope along in front of you. Its path is indeterminate. Pulling that rope will always give a straight line to your hand. There is a reason that Japanese pull saws can be so much thinner than Western push saws.

A downcut blade, instead of pulling the jigsaw downwards into the workpiece as it cuts, tries to launch it skywards. That means the operator has to push downwards on the machine to keep it in place, reducing ability or sensitivity to guide the tool.