How to cut a through mortise in the shape of a stair handrail at a 42 dgree angle

[Mike DeRegnaucourt]

I have a project where I need to cut a really difficult shape through a 3/4" board at a 42-degree angle. The difficult shape is a stair handrail that intersects the board at a 42-degree angle. The handrail needs to pass through the board. I am having a very difficut time trying to figure out how to cut the "hole". Basically it is a mortise but the shape of the mortise is the profile shape of the handrail but needs to all be cut at the 42 degree angle. This is not a rectangular through mortise but the odd shape of the handrail.

I was thinking I could cut this mortise on my scrollsaw with the table tilted to 42-degrees but the problem is when following the sketched profile of the handrail the top portion is angled correctly but when getting to the 180-degree (bottom) cut it is angled the opposite direction. This is because the workpiece is turned to follow the cut line. Would this be something for a jigsaw where the tool is turned as opposed to the workpiece?

I have been Googling for a solution but trying to describe what it is I am wanting to accomplish has not produced the search results I am looking for.

Thanks,
Mike

[Malcolm McLeod]

Have you looked at a uni-directional scroll saw blade...??? The work piece can maintain the same orientation on the table, and the blade cut in the direction dictated by the profile.

[Mike DeRegnaucourt]

Thank you Malcolm! I was just wondering about that. If I keep the board always oriented in the same direction and just follow the shape of the handrail profile, never rotating the board that should maintain the angle I need.

I will go look to see if I have one of the omni-directional blades and give it a test.

Thanks again!

[David Walser]

Mike -- This is NOT an answer to your question. I've never seen anyone do what you're asking about. However, I've seen people make it look like they've done what you want to do. Will it suffice if it looks as if the handrail went through the board? If so, you can make a square, rectangular, or round mortise, through the board. Then, cut your handrail at the appropriate angle where it would be halfway through the board. Then, cut a tenon on each end of your handrail that matches the mortise. You should be able to then sandwich the board between the two ends of the handrail. (If the board is less than, say, 2" thick, you may want to use a long loose tenon to ensure there is enough meat to hold the joint securely.) If the shoulder cuts are done properly, it should appear as if the handrail passes through the board. You can make the illusion even better by inlaying the handrail into the board 1/16" to 1/8" on each side. What I'm describing isn't easy, but it's a darn sight easier than what you said you wanted.

HTH

[Kevin Jenness]

I think David is on the right track. Unless there is some reason that the rail must run through you will get a better result by cutting the rail on either side and rejoining the sections with a loose tenon.
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[Jim Becker]

I'm with Kevin and David...simulate the through and through at the surface but use a half-lap tenon in an easier to cut rectangular through mortise to "reassemble" the rail within whatever it's passing through. The reason I mention the half-lap for the tenon is to keep it longer on both sections for a stronger glue joint to the length of rail.

[William Hodge]

Tenons on handrails is traditional, for a reason. It's a strong way to attach the hand rail to the newel post, and it's easier than an angled cope cut. I haunch the tenons as needed to avoid angled mortises, if possible.

[Mike DeRegnaucourt]

Those are all great ideas. Last night I dug through my scroll saw blades and found a spiral cutting bit. I then traced out the profile of the handrail onto a scrap piece of wood. I then loaded up the spiral blade into my scroll saw and tilted the saw to 42-degrees. I proceeded to cutout the profile while always keeping the board oriented the same direction throughout the entire cut. Side note, cutting on a scroll saw with the head tilted 42 degrees and using a spiral blade is not the easiest thing to do while trying to stay on the line. After I had the "hole" cut through the board I test fitted on a handrail I have set at 42-degrees and it matched up pretty well and slid of the handrail. If I stick with this method, I might need to get a better spiral blade and go nice and slow. The blade I used last night was causing the board to vibrate a lot ( might be due to severe head tilt of scroll saw) which ultimately makes it difficult to follow the line perfectly.

Another problem I have with the project is that I will probably have to make the board in two opposing halves because the handrail cannot be removed from the newel post without destroying the handrail or messing up the newel post by cutting it since the rail is mounted to the newel post I assume with glued in dowels or tenons. The only way to remove the rail would be to cut it at the newel post and I would not want to replace the nice railing. The project involves "cladding" the old newel post to provide the look of a Craftsman style newel posts but still retain the original newel posts underneath since everything is already very sturdy and rigid (no floppy newel posts or rails). Building the cladding should be easy-peasy except for making this tough through cut.

I will have to look further into the method described by David above. The link to the photo Kevin posted was hilarious!

Thanks again all for such great ideas.

[Kevin Jenness]

Handrails are often connected with hanger bolts. Take a look at the underside of the rail where it meets the posts to see if there is a plugged hole or an access hole under the filister between the balusters in which case the rail could be removed and dealt with as described.

What is the reason for this project?

[Jim Becker]

Handrails are often connected with hanger bolts. Take a look at the underside of the rail where it meets the posts to see if there is a plugged hole or an access hole under the filister between the balusters in which case the rail could be removed and dealt with as described.


This is the method I used for my own recent project...they were specially made, articulated hanger bolts that could support whatever angles are required and totally disappear once the underside of the rail is dealt with.

[Edward Weber]

Cut out hole to rough size and use an OSS to shape, with table tilted to your desired angle.

[Mike DeRegnaucourt]

Hi Kevin,

The reason for the project is they want to upgrade their newel posts to give them more of a Craftsman style but without taking apart any of the railings or existing newel posts since they area already very sturdy. They want to upgrade the looks so I thought by cladding the current newel posts with some 3/4" oak, that would give them the new look they want but not take anything apart. In an ideal situation, I would just dismantle the handrails, build new box newel posts and then cut the handrails back an additional 3/4' on each end and then reattach the handrail to the new larger newel posts. However with the restriction of not dismantling or cutting any of the existing star pieces, I came up with the solution of "cladding the old newel posts in 3/4" oak pieces and this would change the older smaller and a combination of round and square to a more classic Craftsman style newel posts. I hope that made sense.

[Mike DeRegnaucourt]

Cut out hole to rough size and use an OSS to shape, with table tilted to your desired angle.

I like that idea too but I do not have an OSS that has a tilting table.

[Mike DeRegnaucourt]

This is the method I used for my own recent project...they were specially made, articulated hanger bolts that could support whatever angles are required and totally disappear once the underside of the rail is dealt with.

There are not plugged holes. I believe it was glued or epoxied using mortise and tenons.

[Jim Becker]

I clearly missed that you were doing a wrap of existing posts...my bad.

[Mike King]

Why not use hand tools? Rasps, chisels, and good layout ought to work.

Mike

[Mike DeRegnaucourt]

I clearly missed that you were doing a wrap of existing posts...my bad.

No worries. It was a difficult situation to describe. Thank you Jim for all the suggestions and help. Once I get this project done, hopefully I can share pics of the end result.

[Mike DeRegnaucourt]

Why not use hand tools? Rasps, chisels, and good layout ought to work.

Mike

That is definitely a possibility. I do not know how accurate my skills are with hand tools maintaining the 42-degree angle and the oddball shape of the handrail.

[Mike DeRegnaucourt]

I have another idea rolling around in my head that I may try. Not sure if it will work but it might be worth a try. If it works, I will be sure to share.

[Kevin Jenness]

That is definitely a possibility. I do not know how accurate my skills are with hand tools maintaining the 42-degree angle and the oddball shape of the handrail.

It seems difficult but doable, the difficulty depending on the handrail profile. Since the board has to fit well on only one face you can flare out the backside of the cuts and concentrate on scribing the fit where it will be seen. I can't imagine getting a good result without hand fitting, starting with overwidth pieces carefully jointed to glue together once you have sneaked up on the profile cut. By the time you get to that point you may wish you had pulled the handrail.

[Mike King]

That is definitely a possibility. I do not know how accurate my skills are with hand tools maintaining the 42-degree angle and the oddball shape of the handrail.

ah! An opportunity to refine skills!