Page 1 of 2 12 LastLast
Results 1 to 15 of 23

Thread: Bigger Convex Curve than #18 Hollow Moulding Plane - How to?

  1. #1

    Bigger Convex Curve than #18 Hollow Moulding Plane - How to?

    Hello,


    I'm interested in trying to reproduce some picture frame moulding which incorporates a wide (2.5 - 3 inches / 60-80mm) shallow convex curve. I'm awaiting the arrival of the largest hollow plane #18, which I believe, produces a 1.5 inch wide convex curve but this is about half the size I require. And I haven't seen any individual moulding planes with this profile.


    Can anyone recommend a hand tool process to produce this kind of curve on moulding?


    Is there a reason that hollow and rounds stop at this width?


    Many thanks, Paul


  2. #2
    Join Date
    Jun 2008
    Location
    Charlotte, MI
    Posts
    1,523
    Here's how I would do it. First, lay out the curve on the end grain of the wood, then plow grooves of various depths in various locations so that the bottoms of the grooves come to or very near the curved line. Split off the waste between the grooves with a chisel, then carefully finish plane the curve using a regular bench plane, finishing with a curved scraper if needed. If the sides of the curved piece are tight to another piece, you might need to use an open sided plane to finish the work in order to cut right up to the edge.

    Failing that, if you are in a tool making mood, you can always make or modify an existing plane to imbue the sole with the proper radius.
    Your endgrain is like your bellybutton. Yes, I know you have it. No, I don't want to see it.

  3. #3
    Making a moulding plane three inches wide would not work well because the shaving has to get all the way out the side of the plane. I would rough the moulding out with a jack plane. Use a marking gauge on each edge so you know how deep you are going, but do the rest by eye. You are not talking about very much depth here so it should not take very many passes. Then smooth things out with a smoothing plane. When using the smoothing plane, concentrate on just altering the angle very slightly from pass to pass, rather than trying to eliminate a particular ridge left by the jack plane.

    If you were doing a lot of this moulding, you could alter a wooden smoothing plane to have a slight concavity on the sole and on the iron. This takes a lot of work and skill to get going, although in the long run it would yield the nicest surface with the least effort.

    A hollow plane that is 1.5 inches wide does not just produce a 1.5 inch wide moulding. It produces a moulding that has a radius of about 1.5 inches, but this moulding could be a half inch wide or three inches wide, whatever you want. And actually if you had a 1.5 inch hollow plane, you could alter it to cut a much bigger radius. I doubt you are making enough moulding to justify the trouble.
    Last edited by Warren Mickley; 10-04-2018 at 9:55 AM.

  4. #4
    If I had a lot of this work to do, I'd consider making a round bottom "Krenov" style moulding plane, with the shaving escaping out the top. In my view, a traditional style moulding plane would be a prohibitively lengthy and difficult investment for a single use tool. The glued-up plane works as well as a traditional style construction.

    For a lesser effort, I'd go my 10-1/4 (because it cuts all the way to the edge of the plane) to rough out the cove (possibly with saw kerfs for a deep cove), refine a bit with a narrower rabbet (rebate) plane, and then maybe go at the refinement with a No. 18 or a suitable gouge on the high spots, and finally finish the surface with a curved scraper.

    For the "tailed species" such a cove is made with an angled cut across the blade of the table saw. Busy set-up and requires multiple small bites to avoid damage to the blade messy surface on the work. Lots of noise and saw dust involved. A somewhat dangerous practice even by table saw standards. Requires removing all safety protections. I've done it; don't like it at all. Not likely to ever do it again.
    Fair winds and following seas,
    Jim Waldron

  5. #5
    Join Date
    May 2016
    Location
    Northeast PA
    Posts
    527
    +1 on using a jack and/or smoother to rough out the curve. If you have a cheap old $2 flea market handsaw laying around you could always sacrifice it to cut out a card scraper and grind it to match the radius that you are trying to reproduce. I’ve done this before and it works very well for final fairing of the curve, but you have to get close to the proper shape using the planes first.
    ---Trudging the Road of Happy Destiny---

  6. #6
    Is there any reason you can’t just eyeball it with the 18? I should think that you could get so close that the ripples would be hard to see by eye and they’d be small enough that a few passes with a card scraper would be all that’s needed to get it perfect.

    I don’t have a ton of molding experience, but when I’ve done it I never actually made my curves match the profile of the planes I own. I just did what looked good to my eye and then grabbed what was close, erring on undersizing for the rounds and oversizing for the hollows (or maybe I have that backwards).

  7. #7
    Join Date
    Jun 2010
    Location
    twomiles from the "peak of Ohio
    Posts
    12,120
    If I remember correctly...a conVEX curve is like the state of Ohio....low on the edges, high in the middle? If so...just hand plane the curve....and clean up with a scraper. Draw the profile on the ends, plane away what is above the line....or, get a handrail plane.

  8. #8
    Core box plane? But a one off plane like others mentioned would probably be easier.

  9. #9
    Join Date
    Jun 2010
    Location
    twomiles from the "peak of Ohio
    Posts
    12,120
    IF he was doing a concave molding......as in a cove.

  10. #10
    Join Date
    Sep 2007
    Location
    Longview WA
    Posts
    27,347
    Blog Entries
    1
    As others have mentioned doing this with a regular bench plane with the aid of a rabbet plane might be the easiest way if you do not plan on doing this for the rest of your life.

    A starting point may be to make a gauge from a thin piece of wood or plywood to check your work. It likely would be too difficult to make a scraper with an arch cut into for use as a gauge and to do a little clean up if needed.

    A #18 plane, theoretically, has a radius of 18/16" or 1-1/8". This would make a 2-1/4" diameter circle. If you have a large round sole plane the radius could be modified to make a shape more to your liking.

    Remembering the difference between concave and convex is easy with a little helper. Concave goes in like a cave. Convex rises like a hill there to vex me when walking.

    jtk
    "A pessimist sees the difficulty in every opportunity; an optimist sees the opportunity in every difficulty."
    - Sir Winston Churchill (1874-1965)

  11. #11
    Join Date
    Feb 2014
    Location
    Lake Gaston, Henrico, NC
    Posts
    8,973
    Before I started accumulating molding planes, I'd use the table saw, and shoulder plane. Use the piece you're matching to place over the table saw blade to set the fence position, and height of blade not quite touching the piece. Take that cut. Move barely one blade width over, and repeat. Once as much of that is done as possible, the shoulder plane can even out the ridges. Scraper and/or sanding sponges finish. Lacking the table saw, the same idea can be accomplished quite a number of ways.

    It's just a lot more fun with molding planes.

    I wouldn't bother to make, or modify a plane for one piece of molding.

  12. #12
    Join Date
    Sep 2007
    Location
    Longview WA
    Posts
    27,347
    Blog Entries
    1
    Quote Originally Posted by Tom M King View Post
    Before I started accumulating molding planes, I'd use the table saw, and shoulder plane. Use the piece you're matching to place over the table saw blade to set the fence position, and height of blade not quite touching the piece. Take that cut. Move barely one blade width over, and repeat. Once as much of that is done as possible, the shoulder plane can even out the ridges. Scraper and/or sanding sponges finish. Lacking the table saw, the same idea can be accomplished quite a number of ways.

    It's just a lot more fun with molding planes.

    I wouldn't bother to make, or modify a plane for one piece of molding.
    This seems like a lot of work.

    The plane could be used to put a light curve on a lot of pieces in the future.

    jtk
    "A pessimist sees the difficulty in every opportunity; an optimist sees the opportunity in every difficulty."
    - Sir Winston Churchill (1874-1965)

  13. #13
    Join Date
    Feb 2014
    Location
    Lake Gaston, Henrico, NC
    Posts
    8,973
    I needed it that day, and that was probably at least 35 years ago, before I was as well equipped as I am now. I don't remember how long it took, but do remember finishing that job that day. It couldn't have taken that long. Years later, my picture was in a small town newspaper making a short piece of large bed molding, on sawhorses on the sidewalk in front of the house it was going on, to replace a rotted out gable cornice molding, with hollow and round planes. For one piece of molding, any way to get it done, with what you have at hand, is the way to do it.

  14. #14
    Quote Originally Posted by Tom M King View Post
    I'd use the table saw...Take that cut. Move barely one blade width over, and repeat.
    That sounds like a pain. Why didn't you just run the piece through at an angle to cut the cove in just a few pass? Just curious.

  15. #15
    Join Date
    Sep 2007
    Location
    Longview WA
    Posts
    27,347
    Blog Entries
    1
    Quote Originally Posted by Mike Lemon View Post
    That sounds like a pain. Why didn't you just run the piece through at an angle to cut the cove in just a few pass? Just curious.
    Because he wasn't cutting a cove. He was cutting a rather large bead, even though it was shallow, it was a raised form.

    Basically make the center cut, move the fence a kerf width, slightly raise the blade, then make two cuts, swinging the piece end for end between cuts with the same setting. repeat until done.

    jtk
    "A pessimist sees the difficulty in every opportunity; an optimist sees the opportunity in every difficulty."
    - Sir Winston Churchill (1874-1965)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •