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Easiest way to cut this board?

5K views 54 replies 11 participants last post by  LRM 
#1 ·
I am using a piece of 3/4" plywood and need to cut these perimeter notches as shown. What are you guys' suggestion as to the least labor intensive way to get this done.

My first thought is to drill holes (OD of the width of a jigsaw blade) at all the inset corners. Clamp a straightedge on the hole center lines as a guide and jigsaw the lengthwise sections. Use same method for inset cross cuts. When I'm done with this, none of these notches will show.

I am hoping there is a more efficient way to do this?
 

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#2 ·
If you are only doing one you would probably be better off cross cutting the notches on a table saw holding the plywood vertical. Then cut between with a jig saw or bandsaw. If you had a lot of them to do I would make a pattern and cut it out with a router. Plywood wears badly on router bits but it saves on labor.
 
#5 · (Edited)
Yes, I will be doing many of these. A jig would be an excellent idea but like you said I wold probably go through quite a few router bits. I might be able to build some kind a jig to hold it in place vertically for my table saw as well.
 
#7 ·
Make a pattern using Masonite/mdf and a flush cut pattern router bit.
That might work for me. Having a pattern/jig so that I could just zip around it would be ideal. Thanks for the tip.
 
#8 ·
I would like to have the inset corners @ 90 degrees for a tighter fit but using a jigsaw or table saw seems to be the only way to do that. I really don't trust myself to hold it upright and run across a table saw. I would have a complete hack-job when I was done I'm afraid, LOL.
 
#10 ·
Thanks George. That is sounding more and more like the best route. I feel that no matter how I do it it's gonna required a good bit of labor. I also have to do the 4 side panels as well they interlock with the floor piece I have shown.
 
#18 ·
outside the box ......

Instead of the cutting the notches, glue/add them on. Set up a jig for spacing them and clamping them, make all the small 3/4" pieces and go for it. The jig would be a larger piece of plywood with rails screwed on around the perimeter and wedges used to force another rail inwards for pressure.





:vs_cool:
 
#19 ·
Instead of the cutting the notches, glue/add them on. Set up a jig for spacing them and clamping them, make all the small 3/4" pieces and go for it. The jig would be a larger piece of plywood with rails screwed on around the perimeter and wedges used to force another rail inwards for pressure.
:vs_cool:
Very good idea. However, I am just starting to build caskets and need a lot of strength in the bottom and corner joint. I'm not sure I would trust that much weight to glue.
 
#21 · (Edited)
well then ......

Typically a good glue joint has equal strength to the surrounding wood.
However, edge gluing to plywood may not be. I think if you like the concept, you could experiment with strength tests very easily. If it would save time it may prove worthwhile.



Now that we know the reason for the notches, I would suggest making them with rounded shapes that conform to the radius of a 3/4" router bit, like finger joints. This is still very labor intensive and probably not necessary for the floor of a casket. Assuming you want a flush bottom for sliding, that becomes the design parameter. How do we make it flush and strong, no dados, but a rabbet may work fine. We are looking to increase the glue surface area for greater strength.

https://www.google.com/search?client=firefox-b-1-d&q=joinery+at+right+angles

Possibly a bit more thought would turn up a joint that will satisfy all the requirements ...... :vs_cool:
 
#22 ·
"a lot of them" - enough thickness that standing them on edge and routing a 3/4 deep "groove" / pass thru multiple sheets at a time would work?
clamp a board at the exit side to minimize tear out...
a spacing&clamping jig for the router is an easy build.

inside corners square or rounded?
 
#32 · (Edited)
See if this is any better. (Pardon my Drafting skills, I just threw the dimensions on here, will clean it up later.) Some of these dimensions are to the hole center and some are the notch itself. Once everything is assembled, the gaps of the hole will be filled in and covered.
 

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#26 · (Edited)
#31 ·
Notching a casket like this gives it added strength without having add other pieces inside to make it strong. When glue and screw the box together it will be rock solid.
 
#29 ·
These boards are six feet long. I would insist on a VERY massive, carefully built jig to hold that board before running an end or a long side over any table saw. Frankly, the board is too large for a table saw without a carefully planned jig that includes a lot of side support on four sides. It is especially important for those end cuts.

I prefer a router solution. If you are making a lot of them, consider buying a pure carbide bit.

No matter how you make them, I see these notches like a box joint in one form or another. Since you are making a lot of them, I would build a solid jig that you can use over the years. The jig can be guided by the previous notch, or it might have all the notches spaced and ready to go one after the other. Think ahead for what changes you might want in the future - different notch spacing, for example.
 
#30 ·
Very good and useful info. I would love to have a jig. Do you have any ideas you could scribble down on paper to help me get a better image of what you are describing?
 
#33 ·
You could use a router with a tongue and groove bit to cut a groove in the edges of the panel. And then glue on the tabs which you make out of the same plywood with the groove attached.

To make the tabs you would first route the tongue to match the groove on the main panel. Then rip off the narrow piece and cut the the tabs to size and the glue in place.

Since I don't know the end use of the panels I cannot say if this is a satisfactory solution. More context is going to be helpful.
 
#34 · (Edited)
Thanks for your suggestions.

The first picture I posted above is a 3/4" plywood floor for the casket. I will be using 1x12 "whiteboard's" for the sides and ends. The 1x12's will be notched on the ends and bottom to match up with the slots in the bottom ply. All 5 pieces will interlock together with glue and screws to form a solid box. The notches do not have to perfect as long as the sides of the notches fit snug. Doing it this way I will be able to screw it all together from the side and bottom for greater strength. I hope I have explained it a little better.

It will be similar to this:
 

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#35 ·
"Doing it this way I will be able to screw it all together from the side and bottom for greater strength."


If you have done a proper glue job the screws will add nothing to the strength. If this design is driven in any way be a desire to use screws you might want to revisit.


George
 
#36 ·
Good point George and thank you for touching on that. However, this design is a proven design that is driven by having the personal security in my mind for all the strength I can achieve. I do not trust glue alone regardless of the fitment or regardless how much of a expert woodworking a person is. I have seen glue come lose with perfect fits and joint. Can you imagine the liability I would have on my hands if some unforeseen crazy thing happened like a casket coming loose at any place during a funeral service or while being transported??? That could be caused by the funeral home dropping it after it left my possession or who knows why. I worked for a funeral home and I have seen some things that shocked me. That is a scenario that I will NOT be a part of so I will be using plenty of screws and glue for my own peace of mind whether it is needed or not. Yes, when it leaves my possession it WILL have proper fitment, glue and screws. :thumbsup:
 
#42 ·
I know that your original post was "how to cut these".


I am in the camp that would recommend finding another joinery method, equally strong but more tool/skill/shop/time friendly. if this box is being skinned over, its appearance is n/a, and opens you up to almost any type of joint.


simple yet strong would be a 3/4" groove 3/4" up from the bottom edge that the bottom ply would rest in. glue and screws from the side would be strong. stronger yet if a 3/4" x 3/4" cleat ran around the very bottom peripheral, screwed and glued to both the sides and the bottom.


it is likely that you may have to impose weight restrictions on most any design you make, with more reinforcements employed as the weight increases. huge difference in box needs for an 80 pound load vs a 480 pound load.
 
#43 ·
I agree completely. I am trying as hard as I can to lose the notching design as originally posted. I am now looking into an alternate joining method as you have mentioned. Are you talking about something like a Rabbet joint at the bottom?



I will be load testing these before they leave my shop as well.
 

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#48 ·
Floor construction .....?

Is there a "standard" type of floor construction in the industry? Could you use thicker material, like 2 Xs glued up? How much is weight a consideration? The additional weight from 2 Xs would be double that of plywood. How much does a finished casket weigh.... empty of course?


Are there any cross members permitted? Would a torsion box type construction be feasible? I'm thinking 2 pcs of 1/4" plywood on a 2" thick grid made of 3/4" Pine. How are the carry handles anchored and what are the strength parameters per handle?



How much would a better grade of wood like Cherry or Mahogany increase the cost? Is the whiteboard a requirement, or a cost factor?


How heavy is the lid and does it fold/hinge in two sections? How much does the upholstery weigh? Does the gurney play a role in the design of the bottom.... needing it to be flush for instance? Is it a sliding or rolling movement to load and unload? Does the gurney follow the casket into the hearse or is it left outside? How many times is the casket transferred on or off during the whole process?


:vs_cool:
 
#49 · (Edited)
Most of the answers to these questions could be considered relative and average based on so many variations to caskets. Here is my best shot. Lots of really good questions.

Is there a "standard" type of floor construction in the industry? No, just needs to be strong

Could you use thicker material, like 2 Xs glued up? not really, that would add too much weight

How much is weight a consideration? Very much a consideration. Sometimes there aren't enough pal bearers and it makes it very difficult for 3-4 people (or less) to carry a casket uphill & several feet way.

The additional weight from 2 Xs would be double that of plywood. How much does a finished casket weigh.... empty of course? approx. 200 lbs +/-

Are there any cross members permitted? No

Would a torsion box type construction be feasible? No

I'm thinking 2 pcs of 1/4" plywood on a 2" thick grid made of 3/4" Pine. Excellent way to gain strength but that might even be a bit too much for this application.

How are the carry handles anchored and what are the strength parameters per handle? Typically they are bolted through the side wall with a small piece of ply or hardwood on the backside for added strength. Somewhere around 30 lbs of pull on each handle.

How much would a better grade of wood like Cherry or Mahogany increase the cost? Significantly, of course if a customer wants that kind of wood, I will build it. For now I am just hoping to get my first few done with whiteboard since it is so readily available, can get in 12" wide easily, and for a cheap board; looks really nice stained.

Is the whiteboard a requirement, or a cost factor? No, it being less expensive is the reason. I know of a couple other casket makers who only use whiteboard with great results.

How heavy is the lid and does it fold/hinge in two sections? Yes, I offer a hinged one piece lid (full couch) or a hinged split lid (half couch). The lid only makes up somewhere around 30-40% of the overall weight

How much does the upholstery weigh? virtually nothing, it is just foam and linen.

Does the gurney play a role in the design of the bottom? No. Needing it to be flush for instance? Yes, it needs to be flush for when the gravedigger is sliding the lowering device straps from under each end once it is in the vault.

Is it a sliding or rolling movement to load and unload? Both, it slides out of the hears onto a accordian cradle that has wheels and is then rolled in and out of the home and back to the hearse

Does the gurney follow the casket into the hearse or is it left outside? Yes, it is stored inside the hearse. The hearse has a bed of rollers.

How many times is the casket transferred on or off during the whole process? After body prep, the body is loaded into the casket, the casket is rolled into the memorial area for the service. After the service it is rolled to and slid into the hearse for transport to the cemetery. It is then slid out of the hearse and back on the accordian cradle where it will be rolled as far as possible towards the gravesite. From there the pal bearers will carry it by the handles to the gravesite and load it onto the lowering device (which also has rollers). It is loaded onto the lowering device from one end and rolled into place. From there the rollers are removed, the casket now rest completely on the 4" wide straps where it will be lowered into the vault.
 

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#52 · (Edited)
So, based on everything that has been discussed on this thread thus far and assuming I will be using the "butt joint" method:

1. Confirmats or wooden dowels?

If Confirmats, on a 80" long side panel board, how many (spacing) along the bottom where it joins the floor?

If Wooden Dowels, on a 80" long side panel board, how many (spacing) along the bottom where it joins the floor?

Confirmats and ply?
Confirmats and whiteboard?
Dowels and ply?
Dowels and whiteboard?

Of course, used with Titebond glue, I am looking for the strongest configuration from the examples above.

2. Suggestions for using all white boards for the floor or plywood?

I DO NOT mean to belabor this topic but as I have explained, there can be absolutely NO room for failure with my joinery. So, if I seem a little nit picky over this, forgive me. I just want to provide the best possible products with no chance of my workmanship failing. If there is a failure, it will be with the quality of wood or because someone other than me drops & damages the casket or something of that nature.

Thanks,
 
#53 ·
#55 · (Edited)
So, why not use a nicer screw as a detail? these brass plated screws have a larger head and are driven with a hex driver for ease and surity:
https://www.mcfeelys.com/screw-fast...ws-brass-plated-steel-hex-drive-qty-1000.html

Here is a section view (below) of one side including the lid in the closed position. All the screws, dowels, confirmats will be hidden. I am using trim pieces that are glued on around the bottom edge and around the top edge. This will hid any fasteners and such. I will also smooth all the sharp edges to a more rounded look.





High end cabinet makers that use dowel construction space the dowels on 4" or 5" centers.

Cheap cabinets made from melamine coated (white) particle board use about a 1.3" spacing for the dowels as the particle board is much weaker.

I substitute one dowel for each confirmat I use. I use the confirmats to eliminate the need for many clamps. If you have lots of clamps, the dowels will work fine on their own.

You should probably establish some reasonable test and test the construction.

About 9 years ago I made a cabinet for the local Starbucks from melamine coated particle board. I used dados and glue only. I recently took it back to my shop for cosmetic repairs as it was looking very shop-worn. The joints were all holding up well. The edge banding needed to be replaced in a few spots (I replaced them all). And I added rubber feet as the particle board was getting wet when they mopped. If I were doing this again I would look for a better way to cover the edges and I would have put on the rubber feet right from the get-go.

A lot depends on how important it is to you for the thing to stay together. If it is very important, then test.
Yes sir, it is very important. I honestly don't mind doing the stress tests. Once I have chosen the best method for my use, I will test the first couple units I make mainly just to satisfy my mind.

I will be using Titebond on every joint as well. Thanks for the dowel spacing info. So, do you guys think I should go with a combination of dowels and confirmats?
 

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#54 ·
High end cabinet makers that use dowel construction space the dowels on 4" or 5" centers.

Cheap cabinets made from melamine coated (white) particle board use about a 1.3" spacing for the dowels as the particle board is much weaker.

I substitute one dowel for each confirmat I use. I use the confirmats to eliminate the need for many clamps. If you have lots of clamps, the dowels will work fine on their own.

You should probably establish some reasonable test and test the construction.

About 9 years ago I made a cabinet for the local Starbucks from melamine coated particle board. I used dados and glue only. I recently took it back to my shop for cosmetic repairs as it was looking very shop-worn. The joints were all holding up well. The edge banding needed to be replaced in a few spots (I replaced them all). And I added rubber feet as the particle board was getting wet when they mopped. If I were doing this again I would look for a better way to cover the edges and I would have put on the rubber feet right from the get-go.

A lot depends on how important it is to you for the thing to stay together. If it is very important, then test.
 
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