So, I thought there was a previous thread regarding this topic, but I searched for 40 minutes and couldn’t find it. Here goes:
Some of my non PG ply has issues with not cutting through in small areas, so it makes it difficult to knockout. I’ve tried a couple different xacto type blades to get in there and manually cut, small drill bits and a rotary cutter, which just doesn’t do the trick. I feel like there’s a tool out there that will work, just something to get in there and cleanly trim what was missed, like a tiny jigsaw, or a sturdy fine saw blade that isn’t too thick to get stuck. Any of you have experience with something that works? Thanks for any help, I feel like there’s an easier solution than the trouble I’m making for myself.
It’s usually a good idea to check non-PG plywood for air pockets and dense glue plugs/knots before placing your design. A laser cannot cut through any of them. (Air doesn’t burn, and you would be surprised at what some companies use to fill gaps.)
You can shine a flashlight through the wood and mark the bad spots, then avoid them when you place the design.
Not really an option at this volume, my goal here is to stay efficient, yet salvage every piece I can after the fact. Lighting and marking pockets isn’t viable, I’m looking for a solution to fix after the fact.
What I’ve had the best luck with is a dental pick…just poke holes along the cut line. Works fine on small areas.
Some of my areas are a little larger where this won’t work, but I think you’re onto something that will help me. I have a weeding pick upstairs, going to go grab that and try this right now.
I use a box cutter actually. Works fine for most things.
If efficiency is your aim it might be worth it to spend the money on better materials with less inconsistency.
I also tend to use a bit more power when I really need to be sure that cuts are going to work. It’s a bit slower but it’s worth it not to have to fiddle with it after the fact.
I also design my cut sheets to have 10% or so extra pieces, so I automatically build in some loss. With most materials the cost per square inch is just not worth worrying about it… all depends on how you value your time. I’m super expensive per hour, so I’d rather lose 5-10% of my materials instead of having to do extra labor to try to finish janky cuts.
A box cutter is one of the better solutions I’ve found.
Yeah, once I’m through this material, which I have a lot of, I will probably upgrade. I’m looking to get through this long term, just to help save a few pieces per sheet without spending too much time on it. I’ve run into this issue on all materials though, even PG stuff from the glowforge shop, so I’m really looking for a nice tool that can help from here on out in a pinch when I need it. I feel like it could save a decent amount of money over the course of 5 years.
I have this set up as slow as I can without scorch, even a second pass with a lower focus and faster cut.
I do the same, I just started getting in the habit of this and it’s saved me more time than anything. Definitely cuts down on the headache just cutting a little extra.
What about a scroll saw blade? Something thin enough you can slip it into the kerf to cut through the missed sections.
Then just moving it manually with your fingers? I had that thought but didn’t know if it would work. I’ll add it to the list. I don’t have a scroll, plan on picking one up, in the middle of a move right now but I’ll have a scroll saw in my new shop.
If you really want to get in there and finish some crazy cuts, a coping saw, or even better, a fret saw will do it. You can get blades for the fret saw thinner than the laser kerf.
Thank you. I am not a woodworker, so tools like this aren’t foreign to me, but I’m not familiar enough to remember them or their specific uses. This is great, I’m ordering a couple of these tonight, a coping saw and a jewelers frame with some fine blades. I can snap apart my ply, so I should be able to maneuver these and fix my specific problem. If not, I’ll look into the fret. Thank you very much, I think this is going to be a great tool to add to my bench for more than just wood.
Someone once posted about success using a palm sander on the back side of incomplete cuts.
When the regular xacto doesn’t work I’ve had a good experience using these micro saw replacement blades (slightly bigger than xacto #11s but fit in the same handle). They’ve been better on straight cuts and soft curves, not so much really tight curves.
Zona 39-925 Replacement Hobby Blades, No33 Micro Saw 32 TPI, 5-Pack
https://www.amazon.com/dp/B000MDLFNQ/ref=cm_sw_r_cp_api_i_pdUgEb9Z9JH5A
Wow, what a cool find! I’ve gotta get some of those.
What about an oscillating multi tool? The blades are usually pretty thin, but I don’t know how they compare to the laser kerf.
Sander or planer can take off a good bit of material on the backside
I have cut a lot of plywood and in my experience, there is no solution for some knots. I did find a little Xacto #15 style saw blade, but it is still too thick to help. And in the case of the worst knots, I don’t think it would help even if it fit. I have run in to knots that wouldn’t cut through after +4 extra laser cuts and shrugged off a craft knife attack too. (At that point the rest of the perimeter is so roasted the piece is ruined anyway.)
If I was going to try again to rescue a cut that was screwed up by a tough knot, I think I would next try a Dremel with some kind of mill bit.
I have the Dremel flexible shaft somewhere, so you could hold the bit like a stylus. Your design would need to let you come in from one waste side to attack the knot though, so this wouldn’t work for all projects.
But honestly, if I cannot salvage the piece with a regular craft knife, these days I write it off and re-cut.
I stand by my pre-cutting 10% extra parts if time is your currency.
The blades look a bit to large for the kerf, but to me, it looks like it would work for some cuts. I appreciate the idea. I’ve seen these in the past and wondered, I might try and track down a friend at some point to see if I could test it out. You can never have enough tools, I’ll probably add one of these, it looks incredibly useful.