what type of saw or similar would be most suited for thin slots (photo holders)

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davedoublem

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Hi everyone,

this is my first post so please go easy as I'm not a woodworker or overly familiar with most tools. I'm actually a sculptor that normally works with gypsum plaster and have only ever owned a scroll saw in the past.

I'm in the process of working on a new project making some photo holders with a narrow (2mm-3mm) horizontal slot across various small shapes. These might measure no more than 100mm x 70mm with a depth of between 30-40mm. The slot depth in most cases might be no more than 15mm. An example of some basic shapes might be an outline of a dog with 4 standing legs, body, head, tail. I'm using basic molds of the shape to pour the plaster into, but these are a similar appearance to the types of shapes that might be cut out of wood. The reason why I'm using plaster is I wanted them pretty thick so as to stand up without falling down easily, and it's more cost effective making them out of plaster than wood.

The idea is to cut a horizontal slot across the entire shape so as to hold a photo. On straight forward flat surfaced wood shapes such as standard rectangle photo/display holder, this is fairly straight forward to do, and could even be done with a standard saw. However, if using a dog shape (I have a few different designs), the head may be raised higher than the body, and the body might also be slightly rounded rather than flat so it's impossible to use any kind of handheld saw. I need the slot to penetrate both the head and body in order to hold the photo correctly, and the slot has to be completely level.

I've never actually attempted sawing through plaster, but know that it's possible to drill into plaster fairly easily so would assume if using an appropriate saw it could work just as well. I might only be making one sample of each shape so ideally wanted to do this on the cheap. I would then make a silicone mould from each sample once I have a slot in each and create all casts from these moulds rather than needing to saw each and every photo holder I make.

Can anyone suggest an acceptable tool or bit of machinery for a novice that does't break the bank since it might only be used no more than a handful of times. More importantly it needs to be suitable for plaster? Alternatively It might be wise to send a handful of the finished plaster shapes to someone to cut these slots for me....not sure if there are any companies out there that offer such a service, but there might well be someone on here. I would have a handful of new designs every so often any anywhere from 5-10 shapes at a time.

I appreciate any help.

Many thanks
 
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Perhaps see if someone can 3D print the patterns for you. Most saws will cut plaster but will the plaster stay together. It's definitely not something I would attempt with any power saw.
Regards
John
 
I think the vibration from any power tool would shake the plaster apart. I think I'd just support the piece well and set to it with a fine toothed tenon saw

letting the weight of the saw do the work should mean you can almost wear it away rather than rip it apart
 
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Doctors, or medical staff, use oscillating saws to cut the plaster casts from arms and legs after the break has healed. I don't see why an inexpensive oscillating multi tool such as the Erbauer EMT300-QC, with the appropriate blade, wouldn't work well for you.
 
I cant see how the OP is going to hold a small plaster 100mm x 70mm figure while he takes to it with any power tool in a safe manner as he has no experience with most tools. Would be a a bu&&er of a thing to clamp without breaking it too. Safest bet may be stick it down with double sided tape and try a handsaw. Tenon or hacksaw. Small teeth would be best I think . A hacksaw you could double up the blade for a wider cut if required. Its something that can only be done after a bit if trial and error. R&D time.
Regards
John
 
Is it possible to cut a slot into the mould that would allow you to insert a piece of metal or plastic that would form the groove to hold the picture during the casting stage? Just 'thinking out loud' as I haven't cast plaster since a '70s craft kit thing with what looked like a novelty condom as a mould
 
I cant see how the OP is going to hold a small plaster 100mm x 70mm figure ...Would be a a bu&&er of a thing to clamp without breaking it too. .... A hacksaw you could double up the blade for a wider cut if required.
I'd put two lumps of plastacine in freezer bags to make soft jaws for the vice, if I was doing repeated cuts of the same shape I'd make permant shaped jaws with air dry clay.

I've never heard of doubling up hacksaw blades, but then again its not often that you need a wider cut, especially at that scale
 
Metal cutting wavy toothed blades work well for cutting plasterboard with a jigsaw without breaking it up, so I would think a hacksaw blade would be good, maybe in a pad saw type handle.
 
Maybe look at it the other way around. Get a spare blade for a miter saw (the manual ones, not a power one) and clamp it to a workbench edge or in a vise, and then (whilst wearing gloves), take the cast part to the saw blade and run it slowly along the blade.
 
Doubling up blades in a hacksaw is an old way to saw a slot for a screwdriver - but you'd need several blades to get the 3mm slot - and the pins of a hacksaw are angled so only one blade gets really tight. If you have a friendly butcher (there used to be butchers) they use blades that go into a hacksaw frame and are probably over 1mm thick.
Sawing plaster works - but there is a good risk of the ends of the slot breaking off. Perhaps a very thin blade that does not put much force on the plaster would work - a piercing saw as used by jewellers might do the job (£15 with a load of blades)- but then you will have quite a task cutting both sides of the slot parallel - the saw blade would cope well with cutting across the bottom of the slot after the sides are done. The plaster would have to be very dry or the blade will instantly clog. Using one of those would not need a complicated way to hold the item - someone else could hold it by hand. It would still be a tedious task - but worth the time if you end up with a usable mould.
Or - is there a way to make the initial item in two parts, cut the half-slot then stick the two halves together?
 
How about one of these
https://www.amazon.com/WEN-36704-4-...eywords=Plunge+Saw&qid=1677681445&sr=8-3&th=1apparently according to the poster whose post about them resulted in my joining here about two weeks ago , Lidl UK have them in ATM for about £50.00..they may also have their "clamp on" type guide rails for about £10.00 or so ( here they had them at the same time ) you should be able to do what you want with that / them. 6 different blades supplied with the saw. cut depth 27mm. Deeper than that you'd want a track saw.
 
Hi everyone,

this is my first post so please go easy as I'm not a woodworker or overly familiar with most tools. I'm actually a sculptor that normally works with gypsum plaster and have only ever owned a scroll saw in the past.

I'm in the process of working on a new project making some photo holders with a narrow (2mm-3mm) horizontal slot across various small shapes. These might measure no more than 100mm x 70mm with a depth of between 30-40mm. The slot depth in most cases might be no more than 15mm. An example of some basic shapes might be an outline of a dog with 4 standing legs, body, head, tail. I'm using basic molds of the shape to pour the plaster into, but these are a similar appearance to the types of shapes that might be cut out of wood. The reason why I'm using plaster is I wanted them pretty thick so as to stand up without falling down easily, and it's more cost effective making them out of plaster than wood.

The idea is to cut a horizontal slot across the entire shape so as to hold a photo. On straight forward flat surfaced wood shapes such as standard rectangle photo/display holder, this is fairly straight forward to do, and could even be done with a standard saw. However, if using a dog shape (I have a few different designs), the head may be raised higher than the body, and the body might also be slightly rounded rather than flat so it's impossible to use any kind of handheld saw. I need the slot to penetrate both the head and body in order to hold the photo correctly, and the slot has to be completely level.

I've never actually attempted sawing through plaster, but know that it's possible to drill into plaster fairly easily so would assume if using an appropriate saw it could work just as well. I might only be making one sample of each shape so ideally wanted to do this on the cheap. I would then make a silicone mould from each sample once I have a slot in each and create all casts from these moulds rather than needing to saw each and every photo holder I make.

Can anyone suggest an acceptable tool or bit of machinery for a novice that does't break the bank since it might only be used no more than a handful of times. More importantly it needs to be suitable for plaster? Alternatively It might be wise to send a handful of the finished plaster shapes to someone to cut these slots for me....not sure if there are any companies out there that offer such a service, but there might well be someone on here. I would have a handful of new designs every so often any anywhere from 5-10 shapes at a time.

I appreciate any help.

Many thanks
I have cut similar slots in wood using the the bandsaw, if you know someone with a bandsaw they could help.
 
Perhaps see if someone can 3D print the patterns for you. Most saws will cut plaster but will the plaster stay together. It's definitely not something I would attempt with any power saw.
Regards
John
Beat me to it! The gcode never wears out !! An STL file means any printer can make a new mould.
 
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