Thread: Cutting coves without moulding planes

Paul, I admit you do have some precedent to lean on, neither Stanley nor Preston seems to have clearly differentiated between rebate & shoulder planes when presenting their low-angle metal rebate products in their catalogues, but the majority of British makers did, & I reckon the majority of users would have done so too.

HNT Gordon makes indisputably good planes and his high-angle, BD formula works well for single-iron planes, in most situations. However, imo, it's a bit cheeky of him to call his rebate planes with a brass-channel protector on sides & sole "shoulder planes". I had one for a while, and it was excellent at cutting rebates along the grain, probably better than a SP in many cases, but it couldn't hold a candle to any of my infill SPs cutting end-grain. That sounds too much like boasting, but I'm prepared to put money where mouth is, you can bring any high-angle rebate plane to my shed and we'll do a head-to head with an equivalent width low-angle infill - I'm 99% certain you'll go away a convert.

The subject of how/why the low-angle BU configuration does a better job of cutting end-grain has been discussed numerous times in various threads (with no clear & convincing concensus!). In head to head trials I did years ago, sharpening blades so they formed the same cutting angle as a BU equivalent, the low-angle configuration was consistently better at slicing end-grain than any BD configuration I tried. I didn't have any very low-angle BD planes like a strike-block to compare, unfortunately (& I wasn't going to make one just for that), but I suspect they would come close, since they were the pre-metal-body choice for the job. My theory is that it has to do with the vector forces on the blade when you drop its main axis below 20*, but what little memory of high-school applied maths I retain isn't up to figuring it out! It's not simply a case of extra mass, my 62-clone is about the same size & weight as a #5, but the 62 slices end-grain with an aplomb the #5 could never match.

Cheers,
Ian

Originally Posted by Chief Tiff

That lower moulding is a 1” quarter round with bead, not something you can quickly knock up without snipes, hollows and rounds or the exact sized cutter in a moulding plane. The upper part of the moulding is a more simple 3/8” astrogal that can be made with a beading plane.

I’d be taking up others’ recommendations of a scratchstock for this.

I think it's called a 'cove & astragal' chief (in the one & only book I have that names them), but the naming of mouldings is a very opaque subject with regional & continental variations and far too confusing for my simple brain. Moulding planes with the appropriate profile most certainly exist, I'm pretty sure I had one, once, but gave a bunch of them away to someone who reckoned they could make them work. Sharpening cpmplex blade profiles is not something for the inexperienced, to say nothing of setting one up with worn or even missing boxing! My early experiences with moulding planes were exercises in frustration & resulted in nothing more than kindling wood. I could probably do a passable job nowadays, but I'm so scarred by those early experiences I am not going to try - hollows & rounds are about my limit....

OTH, I get on very well with scratch-stocks......

Cheers,

Update - it's the scratch stock for the win. Instead of worn scraper or saw blade I used a high speed steel blank that I has left over from marking knives I made last Christmas.

I cut it to the inverse of the curve profile using an angle grinder and Dremel rotary tool. Then I filed it with crisp corners and the honed it on a coarse diamond plate. The edge was a decent cutter but like all scrapers it took a lot of passes to form the Cove.

Best thing I made it from what I already had. It formed the Cove, which was the main objective. I didn't ruin the workpiece - my experience with using combination planes to make beads or rebates for mouldings is a loose cutter/fence/sliding section sending it off course.

Do differently, take more off using rebate planes before using scratch stock. By the end the "L" shaped timber block could no longer hold the scraper, because it was thicker than a usual scraper. I suspect a normal scraper/saw blade would not have this issue.

I think a dedicated set of hollows and rounds would have made this a much easier task. But a shop made tool doing it, albeit with more labour and less finesse , is a win.

Thank for tips and leads.

Anthony

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“1/4 round with bead” is the name of the cutter shape as described by Stanley for the 55 combination plane; however it is well known that Stanley often only had a nodding acquaintance with conventional moulding descriptions. The number 116 is the actual cutter needed for that specific size (1” with a 1/4” bead). Unfortunately that cutter was an optional extra; the biggest cutter in the standard set is the #115 which is only a 7/8” cove with a 3/16” bead otherwise I could potentially make some for you.

Originally Posted by Chief Tiff

That lower moulding is a 1” quarter round with bead, not something you can quickly knock up without snipes, hollows and rounds or the exact sized cutter in a moulding plane. The upper part of the moulding is a more simple 3/8” astrogal that can be made with a beading plane.

I’d be taking up others’ recommendations of a scratchstock for this.

Thanks CT

I used a Stanley 45 with bead cutter for the 3/8 top part of the moulding without issue.

I also used it for the 1/4 bead cutter after using bench planes and rebate planes to make a rebate. I then used the scratch stock to form the Cove. The interface between the bead and cove was not perfect, a snipe bill plane would have sorted that.

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Originally Posted by Chief Tiff

“1/4 round with bead” is the name of the cutter shape as described by Stanley for the 55 combination plane; however it is well known that Stanley often only had a nodding acquaintance with conventional moulding descriptions. The number 116 is the actual cutter needed for that specific size (1” with a 1/4” bead). Unfortunately that cutter was an optional extra; the biggest cutter in the standard set is the #115 which is only a 7/8” cove with a 3/16” bead otherwise I could potentially make some for you.

I'm only have it's younger siblings the 45 and 50. I can't afford the extra sliding sections to accommodate the moulding cutters from the 55 on the 45. Agree those cutters would made this an easier task.

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Hi Anthony

After noticing you interested in fluting blades, was reading through some of this post.

Noticed that you mentioned that the combination plane sometimes run off course. This is something I have also experienced and discussed on a prior thread.

When I didn't pay attention to my combination plane could cut into the side wall. Noticed that the error was always on the fence wall side. Looked at the geometry and that suggested that the problem and strength of the error was likely coming from the fence. If the plane tilted slightly the fence could "pry" off the guiding face and pull the the blade into the groove wall.

Scince the purpose of the fence is firstly to provide a "distance" and I suspected was the main source of the cutting error, the fence was modified. I changed to round fence to provide single point of contact. This seems to work well. The plane with the round fence is the one I use for grooving.

It obviously possible to work with a standard fence, but care is essential to keep vertical and perhaps go slow.

Be interested in seeing your coves, if you obtain a suitable flute blade.

Anther suggestion that may be of interest, if you have tearout, Derek Cohen has thread somewhere about adding a back bevel to beading blades to control the tearout. I an sure that idea would work on fluting blades as well.