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.

 

[Kayen]

I'm not clear on a few things here:

When you say stove do you mean a hob? If so, why does it matter if the cut isn't perfect? Hobs have a flange that will cover the cut anyway.

Most sinks also have a flange, so again, what is the problem?

When cutting 40mm Oak, I would turn the pendulum up to the max and apply hardly any forward pressure allowing the blade to cut its own path, especially when cutting with the grain.

You mention corners - if you mean joins, these are best done with a large powerful router.

 

[meccarroll]

If in future you do use your skill saw for the long cuts and finish the corners with your jigsaw you might find the skill saw wants to kick back when you initially plung the blade into the worktop so be very careful if you do try this method and make a jig of sorts to prevent the saw from kicking back.

I to have had similar problems with a jigsaw blade cutting on the skew but it normally only happens when cutting through deep section wood like a worktop. I find using a stout blade with less teeth and taking small cuts at a time of say a few inches (3-4), stop a few seconds to let the blade cool then cut again. I think the blades sometimes get hot and can then start to run off line usuaklly on the underside.

I use an action of moving foward to cut then back off a little then move foward again this seems to help keep the cut straight on the underside and don't be afraid to swap out the blade on thick timber keeping it cool and sharp.

Let the jigsaw motor do the work if you are pushing with any force then the blade will bend so try to keep to light foward movement and keep the blade cool.

 

[mark w]

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
View attachment 191102View attachment 191103

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.

According to Bosch the blades you used are suitable for softwoods up to 50mm thick, your tops are hardwood so perhaps you've used the wrong blade. In my experience a courser tooth, up-cut blade is better for cut outs in hardwood, never use pendulum action as this can cause chipping, cut slowly and let the saw cut through at its own speed without forcing it. Never use a down cut blade (as suggested) in solid wood, they will not cut satisfactorily if at all and will be very difficult to use, if not impossible.
Your cuts at least are angled in rather than out, meaning the clips for the hob if under mounted will have something to clip on to, an outward angle gives very little or nothing to clip to.
A router with a straight, top bearing guided cutter could be used to correct the angle, the bearing running against the top edge of the cut-out.
If it were my mistake and I didn't have a router I'd leave it as it is, the hob does not need ventilation at this point as you suggested and the extra material at the bottom of the cut-out could be argued a benefit. Don't forget to seal those cut edges.

 

[johnnyb]

First off never plunge cut solid worktops. Its lethal. The chance of kick is very high. So it's jigsaw only. The rest is new coarse blade and pendulum. Mafells are OK as jigsaws and don't wander off to much but they can rattle and shake for a reason I've never quite sussed. They will cut nice for a bit then feel like there gonna shake your wrist apart.
Unfortunately once jigsaws wander they tend to wander further and further. Could you do a short jigsaw cut then finish with a new coarse handsaw?

 

[Lons]

40mm solid oak can be a handful for most jigsaws which are best not used for the final cut anyway. I've fitted hundreds of kitchens professionally and would never use a circular saw either. Jigsaw to remove the bulk of the waste then a router to finish is quick and easy. A router is so useful you should have one anyway (I have 4), look for a Lidl / Aldi version if you want cheap, they're half decent and have 3 year warranty.

If you have hand tools you could use a block plane or even a sharp chisel to straighten the cuts.

 

[--Tom--]

Try some practice cuts in the offcut. You have to feed much slower than you expect to keep it vertical you also need to get used to feeding very straight. The feeling of it pulling you in one direction was it telling you the blade was bent.
If you try and wrestle the saw to cut straight or feed too fast you’ll get wonkiness.

With most things there’s a skill to it and practice helps. Helping a friend do a kitchen showed that recently - using the same saw and blades on the same worktop I was getting straight and plumb cuts - he was getting similar issues to you.

 

[Distinterior]

I've also fitted hundreds of kitchens professionally and would choose a tracksaw & rail every time over a jigsaw.....jigsaw to final cut into the corners only.
The tracksaw is far quicker, more accurate and virtually no sawdust when connected to a dust extractor.

Plunge cutting without a kickback stop is dangerous, so i always use one.
A 12 tooth blade in my tracksaw would be my choice if cutting 40mm solid oak worktop.

Edited.
If I were forced to use a jigsaw to do the cut, I'd set it to maximum pendulum, use as rigid a blade as possible with a low tooth count and let the jigsaw cut at it's own pace....I would never use a downcut blade to cut out a hole in a kitchen worktop that was going to have a drop in Hob or sink.

 

[Bingy man]

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...

I have an old atlas copo that cuts worktops with ease with the blades I’ve referred to . Underpowered refers to the fact you are cutting oak which is problematic for most jigsaws . It’s not easy to get a perfect cut with a jig saw as the blade can wander off the cut line ( at the bottom of the cut line ) but you can’t see it as you are working from above ..usually a few degrees off won’t matter as the fixing brackets are adjustable and you will never see it ..the speed you set is fine but the speed you push it through the material is more important. As above router or a plunge saw to do most of the work then finish corners with the jig saw ..

 

[PerryGunn]

First off never plunge cut solid worktops. Its lethal. The chance of kick is very high.

I'd qualify that by saying that it only applies to a 'normal' circular saw. If you have a track saw then plunge away, it's what they're designed to do.

I'd do the majority of a cut out like this using a track saw and then just finish the corners where the cuts don't meet with a jigsaw or hand saw. Cut slightly undersize and then a final pass with a router to take the last couple of mm off.

 

[Bingy man]

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.

So first off the down cut blade is less likely to splinter the worktop edges especially laminated tops . As for the blades themselves all I can say is they are slightly longer than the normal blades , I’m no expert in tooth geometry but they are stronger and imo sharper than the regular blades hence the price . Try gently pulling the blade against your hand .. they are also thicker than standard blades and are less likely to wander off the line . A test cut might for example give a 3 or 4 deg left or right of the cut line so setting the jig saw at a slight angle can compensate for this slight deflection. But as above if I was in any doubt then I would consider my router + jig or the track/ plunge saw . If I’m about to cut a hole in a £400 - £600 worktop I want the aperture in the right place . The op is new to tha game hence my advice is on his skill level . Also as I’ve said if his hob fits into the aperture he’s cut and the brackets engage then he doesn’t need to do anything more to it .