Confirmation for reasons to scribe internal corners on skirting

Discussion in 'Carpenters' Talk' started by ShabbaPlanks, Nov 7, 2006.

  1. ShabbaPlanks

    ShabbaPlanks New Member

    I have just sat a test in college. The question was asked, "please explain in breif why internal corners are scribed on skirting as opposed to mitred?"
    My answer was that a mitre on an internal corner would pull apart if the wood cupped where as on an external mitre those same forces would push the joint tighter.
    My tutor suggested that the answer should read " A scribe is used on internal corners as it gives more play when fitting to a wall out of square."
    My personal feeling is that I was happy with my original answer, and would like to open a debate with him on this issue.
    My books cover scribing, but they do not take into account the reasons why. So I can confidently say I must have gained the information here :). As there are a silly amount of topics covering skirting here I hoped some of those original contributors might once again grace me with their knowledge.
    Finaly I would ask that those who do not scribe to please not reply to this topic as I would like to keep to the subject as oppossed to a debate about scribing or mitreing internal. ;)
    Thanks in advance
     
  2. panlid

    panlid New Member

    great modern education when the teacher tells you the answer;)
     
    furious_customer likes this.
  3. ShabbaPlanks

    ShabbaPlanks New Member

  4. dunc

    dunc New Member

    A skirting joint will open up if it has been inadequately secured. As long as you can get fixings near the joints they will prevent cupping from blowing the joint.

    The general purpose of scribing internals is that they offer the most reliable method of jointing. This is important when considering overall time an a large contract.

    The text book answer is good enough. The scribed joint, which is basically a butt joint, will allow more play during fitting.

    Your answer about cupping is slightly off track, Cupping will occur if it has freedom to do so. It could go either way depending on how the board was cut. You prevent cupping by securing the board suitably. This means fixings near the joint and glues and pins.
     
  5. dirtydeeds

    dirtydeeds New Member

    dunc your first answer WAS correct, its done to avoid wood movement full stop.

    Scribing is NOT done to get MORE PLAY in the joint. Scribing is done to get an accurate tight joint.

    Guys who look for more play in a joint end up with sloppy joints.

    Would you accept open, sloppy, poorly scribed joints on varnished hardwood skirting. Dont expect a customer to accept them either.
     
  6. big all

    big all Screwfix Select

    with a join both suface can shrink towards the wall [both surfaces on the mitre move apart]

    where as on a scribe only one one surface moves away the other one just moves parralelto the face edge off the other

    big all
     
  7. dunc

    dunc New Member

  8. Mr. Handyandy

    Mr. Handyandy Screwfix Select

    Yeah, but if a mitre joint is tapped in tight, it has room to shrink without coming apart.

    AND being tapped in tight, will also prevent cupping.

    If a scribe butt shrinks a millimetre you will have a mm gap


    Mr HandyAndy - Really
     
  9. big all

    big all Screwfix Select

    ok and can you explain exactly how you get your mitres tapped so tight then H A ;)
    short of hitting the nails at an angle i cant see how you can get them any tighter without dammaging the skirting!!!!

    ok you can "overspring" in a bit just cant work it out apart from that ;)

    big all
     
  10. Mr. Handyandy

    Mr. Handyandy Screwfix Select

    ok and can you explain exactly how you get your
    mitres tapped so tight then H A ;)
    short of hitting the nails at an angle i cant see
    how you can get them any tighter without dammaging
    the skirting!!!!

    ok you can "overspring" in a bit just cant work it
    out apart from that ;)

    big all



    You cut them tight if you have an end to end piece(corner to corner).

    If you have a piece that is not full length of wall, you will have a 45° mitre join. You can hit that fairly hard in the middle at the back of the mitre cut, as this will be over covered. To finish the wall, you cut tight again, get your mitre join right and stay tight in the corner, and so on.

    'Tain't rocket science.

    If the other end happens to be an external corner(and mitre) you tap it in real tight before marking and cutting the external mitre, thus tapping on waste wood. It will go back in with a lighter tap when cut.


    Lateral thinking, I always say.



    Mr HandyAndy - Really
     
  11. Mr. Handyandy

    Mr. Handyandy Screwfix Select

    Forgot to say, pretap a couple of nails in, so that you can fit it with one hand after tapping it up.



    Mr HandyAndy - Really
     
  12. goldenboy

    goldenboy Well-Known Member

    This is such a regular subject for discussion. Always scribe internals it is the way it should be done. Mitring internals is bodging. Saddle up cowboys
     
  13. ShabbaPlanks

    ShabbaPlanks New Member

    Did some * just change the topic to a scribe or mitre debate? Did you read my first post in full, replys like that are the reason I could not find the original post I read.
    Anyone worth their salt does not need to make this an issue for discussion......
    Thanks B A, giving the reason as having more play just did not sit well with me. I knew the answer lied in movemant in the joint but could not pin it down.

    Message was edited by: Screwfix Moderator
     
  14. splinter2

    splinter2 New Member

    I think what you're tutor meant by more "play " is that it is easier to adjust a scribe if the wall is out of square ,where as if you try and adjust a 45 degree angle ,you would have to adjust both 45's other wise it will not work
     
  15. goldenboy

    goldenboy Well-Known Member

    Dont have a pop at me sunshine and dont dictate to me what i can and cant post. If you want to dictate what people post become an admin on www.iamalazystudentwhocontinuallypostsquestionsabouthiscollegecourse.com
     
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  16. ShabbaPlanks

    ShabbaPlanks New Member

    Easy Goldenboy
    My post was not directed at you or your reply. The key word is reply. I think it is quite reasonable to ask people to stay on topic, especially on this matter...one mention of skirting and away we go. Perhaps you could read the topic again from the beginning.
    I have mentioned my college course only a few times so no need to make it personal.
     
  17. ShabbaPlanks

    ShabbaPlanks New Member

    I think what you're tutor meant by more "play " is
    that it is easier to adjust a scribe if the wall is
    out of square ,where as if you try and adjust a 45
    degree angle ,you would have to adjust both 45's
    other wise it will not work

    Cheers Splinter
    I dont doubt your right, I am just trying to confirm things in my head, make my own mind up so to speak. I am very happy with my tutor as opposed to last year, just that some times I dont feel able to question in detail with out feeling that I am getting his back up :)
     
  18. big all

    big all Screwfix Select

  19. splinter2

    splinter2 New Member

    Shabba ,as you have already read ,yhere are numerous reasons for scribing skirting.The most important reason for you as a carpenter(as already mentioned by your tutor,it would have been better if he had put the word with after "play")Is ,that by cutting a scribe you have already pre-empted any problems that you might encounter,eg walls out of square,walls that are plasterboarded and pullback when you fix the skirting,walls that have not been plastered flat at the bottom making the skirting tilt(remember the play with advice).
    Scribing also cuts down the margin of error for a carpenterand as a bonus it minimises shrinkage
     
  20. dunc

    dunc New Member

    I really think the idea about shrinkage needs to be sorted. I don't see how any joint will prevent or reduce timber shrinkage. Or expansion. Its the property of the timber and the jointing has no influence on what the timber is going to do.
     

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