Thread: Table Saw: Blade Guard Material

My rationale is that the guard should be transparent and of a material that does not damage the CS blade if it happens to come into contact with it. This pretty much limits the guard to some form of plastic.

Acrylic is relatively cheap and can be worked easily enough with woodworking tools although a negatively raked multipurpose CS blade would be advantageous.
PC is more expensive but being tougher and more flexible than acrylic so thinner sheets of it can be can be used.

Transparent PVC is somewhere in between the two above. My guess is it will be softer than both acrylic and PC so it may scratch a little easier. It will also yellow and craze over time if it is not UV stabilised and is expose to UV.

Another material worth a look is PET (Polyethylene terephthalate) which is used for softdrink containers. I even bought a large family size coca cola once with the idea of trying to cobble together a cheap guard but my son threw the bottle out before I had a chance to use it. I have never seen sheets of PET readily available but I did not look very hard.

If I were to make my own guard I would only use polycarbonate, it is shatter proof, if it is good enough to protect bank tellers it is good enough for me.

I agree with big shed. Polycarbonate, brand name lexan has a high impact strength. It is what is used in safety face shields ect. I tested a piece by attacking it with a ballpain hammer on a anvil.Eventually turned into a fiberous mess but did not crack or shatter. It is easly worked with wood working tools and can be folded and formed with boiling water or carfull use of a heat gun>

Kev

Originally Posted by Kevin-R

. . . . . It is easly worked with wood working tools and can be folded and formed with boiling water or carfull use of a heat gun>

If it is 1 mm or thinner it can be folded at room temperature. It needs to be over folded to retain the bend and the bend ends up with an ~10 mm radius of curvature but it can be bent.

Gareth,

My guard is 10 mm machine guard grade polycarbonate. I wanted it very strong/safe, but at 10 mm thickness it is heavier than most. However, it is well balanced and glides easily. Because it is screwed together, I did not need to bend it.

If I were doing it again I would consider making the sides of the guard and the riser out of 5 mm material. The top, front and back would still be 10 mm so I could screw into it.

If you want to keep it quite light, thin polycarbonate, acrylic or clear PVC would do the job. I made a curved hood for the spindle moulder out of 3 mm clear PVC. It is very easy to thermo-mould, but is not as tough as polycarbonate.

These materials are all easy to work with using sharp, standard woodworking tools.

The aspect I am most pleased with about my guard is visibility. Making the riser and the arms out of polycarbonate increased the polycarbonate cost by $33.00 (an extra sheet), but I did not need to buy any aluminium or steel components. I can see across the entire table from any direction, and I am obsessive about being able to see the blade and all around it.

Thanks All,

Seems PC is the way to go. How thermo-formable is PC? Interesting that it can be thermoformed using boiling water. Ease of thermoforming was one of the things I liked about PVC.

Only tried it once, as a test. Did not go well. It was 10 mm PC.

The material bubbled on the surface before it became mould-able ... maybe I was heating the oil too fast.

At any rate, probably not a bad idea to run a test on an off-cut first.

Okay guys, what's the recommended minimal thickness of PC to use? John suggested 10mm and 5mm (front and sides). If I'm wanting to keep things light, and safe what's a good thickness? I'm thinking if it's thinner I'd end up having to use Al or the likes to join. Whereas as John has suggested if I used 5mm and 10mm I could still screw things together, so in the end they may end up being the same weight. FYI I'm thinking of creating a blade guard similar to the Triton blade guard but bigger to accept at least 100mm ducting:

https://www.woodworkforums.com/f153/p...-guard-166626/

So, things need to be as light as possible keeping in mind I'd be hanging the duct from the roof and fitting it directly to the guard.

Thanks.

Greetings from Saudi Arabia.

Don't put this place on your bucket list.

So far as the guard thickness is concerned, I guess you should first state your requirements. I wanted machine grade guard material, which is why I went for the 10 mm PC material.

BobL used very thin material, probably because he sees his primarily as a dust collector rather than a guard, but I'll let him speak for himself.

Neither is right or wrong. It depends on what you specify as your requirements. The good thing about 10 mm PC for the top, front and back of the guard is that you can screw directly into it ... no frame required. If you are going to make a riser like mine (I love being able to see through the riser ... but that's me), it too will need to be fairly thick on the sides, as this is where the arms hook up and you likely need pretty good strength.

I put in a riser for two reasons. First, so I can see through it. Second, the riser was strong enough to eliminate frames altogether and to hook up the arms to the back of the riser.

Using 10 mm PC everywhere makes for a strong, safe, but heavy unit. Works for me but others may want different things.

Also, I set the height rather than ask the guard to rise up over the workpiece. If you want the guard to rise over the work, you should likely keep things lighter than I have.