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Cut worktop from top or bottom side

Discussion in 'Wood / Woodwork / Carpentry' started by Jupiter01, 18 Sep 2020.

  1. JobAndKnock

    JobAndKnock

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    I'm not a fan of the Bosch spade bits with a screw type centre - I find that they pull in too fast on many materials (including laminated surfaces) making them liable to damage the surface by chipping. Try them out on an off cut (drill from the laminate side) and decide for yourself. If they don't work go and buy yourself an Irwin spade bit - they don't have a screw centre but the design features nickers which are very good at scoring laminate. A 14 or 16mm size should do the trick
     
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  3. opps

    opps

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    I have a 3 Irwin bits that have the threaded centre.

    https://www.irwin.com/tools/drill-bits/speedbor-max-speed-bits-4-short-length-bits

    They sell both types.

    In addition to the threaded Irwins I have some of the triple fluted Armeg ones. They are both definitely faster at cutting through soft wood (than traditional spade bits) but they push my old non lithium 18v cordless Dewalt drills to their limits.And yes they pull themselves in even when you want to stop. That said they are wayyyy faster.
     
  4. JobAndKnock

    JobAndKnock

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    Yes, but I did specifically refer to spade bits, but not speed augers, when talking about the iniquities of bits with a screw lead in my last post. When referring to auger bits in an earlier post I was specifically referring to auger bits (as in traditional auger bits, i.e. the type with spurs which are always run at low speed) and not the modern speed augers which lack any form of spur and are therefore likely to cream cracker a laminate surface. High speed and aggressive cutting is never conducive to clean drilling of laminates in my experience. Neither is using blunt tooling. Is that specific enough for you?
     
  5. opps

    opps

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    Erm, I wasn't disagreeing with you. And nor was I recommending speed augurs for laminate work tops.
     
  6. JobAndKnock

    JobAndKnock

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    Sorry if there was any misunderstanding - I was merely attempting to clarify what I wrote on earlier posts. I've used the modern multi-flute speed augers in the past and TBH I find the cut on them to be pretty rough - but then they are designed to bore quickly through joists, etc for "invisible" work (i.e. stuff that will never be on show like wiring or plumbing) so you can hardly expect first class finishes. A traditional auger bit used either in a brace or at low speed, however, is a completely different animal and will generally make a clean cut into laminate providing it is sharp and not run at stupidly high speeds (a common mistake). Similarly both "old style" spade bits (the ones without a screw point, but with nickers on the outer edges of the cutter) and brad point centre bits are good in laminates, but you do need to buy the correct drill bit for the job to guarantee good results
     
    Last edited: 22 Sep 2020
  7. Jupiter01

    Jupiter01

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    Sorry to persist with this point but if the blade is turning clockwise, wont it always cut into the surface? Even if I am starting on the back end of the worktop (with back facing upwards) and cutting towards the front end? I get how if I was cutting the worktop from the laminate surface, the blade turning clockwise will break through the laminate and hence cause damage.

    When cutting from the backside, I am still not comprehending why cutting from the front to the back or vice-a-versa makes a difference. Thanks for bearing with me...
     
  8. JobAndKnock

    JobAndKnock

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    If you cut from back to front, upside down, the teeth will be rising (from the bottom) as they exit the material. At that point the laminate has nothing to support it and will blow out. If on the other hand you cut from the front, upside down, the laminate, which is rather brittle, will always have particle board supporting it as a backer. It matters little if you get a small amount of blow out on the unlaminated back edge as that will be going against the wall. If you don't believe me try it on an offcut...
     
    Last edited: 22 Sep 2020
  9. Jupiter01

    Jupiter01

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    Would you be cutting from the backside in the above situation?
     
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  11. JobAndKnock

    JobAndKnock

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    No, always from the front to the back and face down with a circular saw. If not you will probably get chipping on the front edge of the worktop because (as stated earlier) when cutting from rear to front at the end of the cut the teeth exit the worktop through the laminate on the front, and that laminate is unsupported (i.e. there is no chipboard oouboard of the laminate on the side where the teeth exit the worktop). In order to cut laminated materials with minimal break-out of the laminate surface it is always necessary that the cutting teeth enter the material through the laminate surface so that the chipboard is behind it to support the brittle laminate. Been cutting this stuff for decades and this is the only way

    Why not draw it out on a piece of paper and check it for yourself?
     
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  12. Ryler

    Ryler

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    This guy achieves a perfect cut with the Festool Ts55..
    From the top.....
     
  13. big-all

    big-all

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    you always cut from the top with a track/plunge saw
    we where talking about a normal circular saw upside down front to back
     
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  14. Ryler

    Ryler

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    (y)
     
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  15. big-all

    big-all

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    thanks for checking though always best to ask if in doubt (y)
     
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  16. Jupiter01

    Jupiter01

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    Does the blade on this seem appropriate for the worktop cut?

    Thanks for all your help.
     

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  17. JobAndKnock

    JobAndKnock

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    See below, duplicated post
     
    Last edited: 26 Sep 2020
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