What's wrong with my circular saw

[Deleted member 174758]

I thought to stop splinter/ breakout you had to support both sides of the cut. So with one rubber edge do you have one good edge and the off cut a bad edge.

On a plunge/rail saw you often don't. Whilst some saws such as my Festools have offside splinter control I rarely use it as most cuts I do leave enough spare material to take one bad side into account. However, some laminates are very brittle, so when dealing with those it is advisable to clamp the guide rail in place then make a scoring cut (a 2 to 3mm deep cut designed to score the laminate surface) followed by a full fepth cut to get the cleanest edge

How clean an edge you need obviously depends on the application - kitchen worktops, for example, only need clean cuts at the outer ends (and then only if the ends are going to be finished with laminate) because the inner ends are joints which will be routed to form a mason's mitre

 

[Deleted member 174758]

Its a dewalt 24 teeth 71/4 blade. Yes also a thin kerf.

Thin kerf, low tooth count - you are asking a lot for a limited number of teeth to do. The thin kerf (something like 1.65mm as opposed to 2.2mm or so for a conventional blade) is also a lot more likely to flex in the cut, especially if the gullets load up and thd blade starts to get warm. In addition I'll bet you have no dust extraction in, which will hasten the gullets loading up

The last couple of cuts will only be 500mm wide and those will be going on my table saw after a rough cut with my circular saw. Table saw I have a 40 and 60 tooth blade to choose from.

Personally I wouldn't cut worktop on a table saw. In general long pieces are just too long to handle safely on the average portable or DIY table saw.

 

[aveatry]

Yes its 1.56mm kerf
Yep I do have extraction for the hand saw.

Personally I wouldn't cut worktop on a table saw. In general long pieces are just too long to handle safely on the average portable or DIY table saw.

Me neither but I am first cutting off the 500mm section that I need + 10 mm and then cutting the 10mm off the 510mm on my table saw with a 60 tooth blade so I am only handling 510mm on the table saw. Its a DE Walt 7485

​

 

[aveatry]

Update. Just cut that last piece of worktop just a small 500mm bit. Cut it off the bigger section 10mm oversize with the circular saw and the cut is pretty good - not happy with it mind you but after a quick sand to finnish the sharp edge most of the very small chips were gone. So next time I will be investing in a 60 tooth blade for it for the best possible cut.
That edge did not matter anyway as it was a test cut and it was cut to the right size on the table saw that has a 60 t blade and to be honest that cut was not massively better than the circular saw.
At least I am no longer getting an off square cut now with the circular saw.

 

[opps]

On a plunge/rail saw you often don't. Whilst some saws such as my Festools have offside splinter control I rarely use it as most cuts I do leave enough spare material to take one bad side into account. However, some laminates are very brittle, so when dealing with those it is advisable to clamp the guide rail in place then make a scoring cut (a 2 to 3mm deep cut designed to score the laminate surface) followed by a full fepth cut to get the cleanest edge

How clean an edge you need obviously depends on the application - kitchen worktops, for example, only need clean cuts at the outer ends (and then only if the ends are going to be finished with laminate) because the inner ends are joints which will be routed to form a mason's mitre

My Festool TS55 is the older generation one. Like you I do a very, very shallow cut first when working with laminate worktops.

 

[Deleted member 174758]

My Festool TS55 is the older generation one. Like you I do a very, very shallow cut first when working with laminate worktops.

I'm the same with my 1st gen TS55 - but most of my panel cutting us nowadays done with a Makita DSP600 (basically a cordless SP6000), and believe it or not Makita actually had a scoring facility on the SP6000 from the very beginning

 

[opps]

I'm the same with my 1st gen TS55 - but most of my panel cutting us nowadays done with a Makita DSP600 (basically a cordless SP6000), and believe it or not Makita actually had a scoring facility on the SP6000 from the very beginning

I do not doubt you. I bow to your superior knowledge- yet again. Tnx.

 

[aveatry]

Just noticed a scratch along the front edge of my last cut 500mm section, on studying the table saw fence I can see a tiny nick in the aluminium that caused it ---- ahhhhh ****.
I do still have some spare so i will have to cut another. I have sanded down the fence nick. but will also add some masking tape on the worktop edge.

 

[big-all]

Just noticed a scratch along the front edge of my last cut 500mm section, on studying the table saw fence I can see a tiny nick in the aluminium that caused it ---- ahhhhh ****.
I do still have some spare so i will have to cut another. I have sanded down the fence nick. but will also add some masking tape on the worktop edge.

thats usual in the respect you would expect the damage to be full length suggesting you are varying the pressure on the fence which is not ideal and can cause wavy edges with variation off pressure especially if the fence is mainly forward off the handle position

 

[aveatry]

thats usual in the respect you would expect the damage to be full length suggesting you are varying the pressure on the fence which is not ideal and can cause wavy edges with variation off pressure especially if the fence is mainly forward off the handle position

It is the full length and this is on my table saw not the hand circular saw. its a small 500 wide piece of worktop but I have also had to trim off the back edge taking it down from 620 to 610 deep and that is the cut that did the damage as I was cutting off the back the facing front edge was against the table saw bench.

 

[big-all]

It is the full length and this is on my table saw not the hand circular saw. its a small 500 wide piece of worktop but I have also had to trim off the back edge taking it down from 620 to 610 deep and that is the cut that did the damage as I was cutting off the back the facing front edge was against the table saw bench.

ok table saw but should still be full length as you will have both a push stick to hold on the fence and another to push through the gap to blade
now iff you just push at the back between blade and fence with a larger bit other side compared to between blade and fence the grip will cause a tendancy to move the work away from the fence even iff its only 0.5mm but as you progress the bit that was approaching the back edge off the fence is now a fraction wedge shaped so now encourages the work tighter to the fence at the front and getting tighter untill the back edge is fully on the fence
soo i predict the fence side with the score on it will have a hollow perhaps 0.5-3mm can you check please

 

[aveatry]

Thanks everyone for your help but I think there is some misunderstanding. The table saw fence has a sharp nick on its aluminium face which has transferred a scratch onto the worktops 38mm facing edge. This happened when I cut a 510mm wide piece down to 500mm for a 500mm wide cabinet.
The nick on the fence lines up with the 18mm cabinet carcass I have been cutting a lot of so is 18mm high from the table which is just about in the middle of my 38mm worktop.

I think it must of happened whilst I was lining up the height of my out feed table and sliding a piece of cabinet up and down the fence and must of caught it with a corner - it can be quit sharp.
The culprit has now been sanded down but will also be protecting the replacement piece of worktop with some masking tape.
Checking the fence for nicks will now become part of my pre cutting routine.

 

[big-all]

glad its sorted lol nicks pencil marks all part off the individuality

 

[aveatry]

OK so now about to re cut the scratched piece with my last piece of worktop.
Would this work
Cut it to 520mm with my hand circular saw then onto the table saw face down but first with the saw teeth only just cutting a few mm to cut the laminate surface then wind the blade up to cut the full depth.

 

[Deleted member 174758]

Maybe, maybe not. Probably not.

When you do a scoring cut using a plunge saw and guide rail it is imperative that the guide rail is clamped firmly to the material before and during the cuts. This is to ensure that the guide rail doesn't move at all between the two cuts. Normally, the rubber grip strips at the bottom of a guide rail are sufficient to hold the it in place for a single cut, but it is very easy to disturb it even by lifting the saw off the rail or just sliding it back to the.start position. Believe me, this I know from personal experience. In this scenario the scoring cut is made first

Trying to reproduce this on a table saw is fraught with problems, but I think if you insist on doing it that way, then think on terms of making the scoring cut first. Not last, where you risk having the almost cut through section just snap off as you handle it. All I'd say is don't expect to get a clean cut all the way through without any steps. You may succeed, you may not.. Are you sure that you aren't just trying to use the table saw just because you have it?

Now we know this is a rip cut (my earlier comments were assuming a cross cut, doh!), just why is it necessary to get a perfect cut? Most times when you rip worktops down in width the rip is going to end up against a wall and have some form of tiling, backsplash or upstand which covers the edge, and always a silicone joint which will also help hide minor discrepancies. Walls are rarely straight, so it's not productive a lot of the time to be ultra precise doing these rip cuts (but it most certainlty is productive to seal the cut edges, even if they get hidden afterwards). It's only on cross cuts at any exposed ends of a worktop that the cut needs to be near perfect (masons mitres are dealt with by jig and router). That's so it can take the laminate cover strip. TBH before I had a plunge saw when doing such crosscuts I'd just cross cut slightly oversize then use my 1/2in router, 30mm guide bush, 1/2in diameter cutter and the outside edge of the worktop jig (clamped across the end of the worktop section) to make a perfect cut edge. The offset from the jig is a little awkward (8.65mm), but doable