Prep Failure

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OK, so i picked up 2 stars and wavy stripes blanks for a project (bolt action) from Woodcraft. Supposed to be acrylic, but I'm not so, sure. I'll explain.
First blank, within 30 seconds of drilling (taking it slow), a big chuck chipped off. I'm thinking "ok, first time drilling something bigger, 3/8" than I'm used to", rookie mistake. 2nd blank went better, started with 7mm then the 3/8". Made it all the way to getting the tube glued and inserted. One side, perfect squaring(again taking it slow), opposite side, crack! even bigger piece broke off. Neither blank salvageable :( (used a reamer)
It looked totally different from my other acrylics, almost looked like resin.
So, what did I do wrong in my process?
I have 2 poly resin blanks waiting to be used, but I want to see if there's a difference in drilling and turning those as opposed to the acrylic(I've made one pen thus far with acrylic).
I know there's a little bit of a learning curve compared to wood, so I'm not going to let this little fail frustrate me (yet lol).
any tips/tricks/advice for a rookie?
 
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Kenny Durrant

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If your drilling on a drill press make sure there’s a piece of scrap wood butted up against the the bottom of the blank. That will help with chipping when drilling. Until you get used to working with the material round off the corners with a sander or bandsaw. When turning work from the outside to the center. That way your pushing material against material instead of off the end. Once I get the blank round I’ll use a skew and taper the ends to the bushings. That way the end of the blank will have some support from the bushing. Not sure if this is part of your problem but it might help avoid other issues. Good Luck.
 
Joined
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If your drilling on a drill press make sure there’s a piece of scrap wood butted up against the the bottom of the blank. That will help with chipping when drilling. Until you get used to working with the material round off the corners with a sander or bandsaw. When turning work from the outside to the center. That way your pushing material against material instead of off the end. Once I get the blank round I’ll use a skew and taper the ends to the bushings. That way the end of the blank will have some support from the bushing. Not sure if this is part of your problem but it might help avoid other issues. Good Luck.
The blowout is on the end I'm drilling, not the exit side. I use a drilling clamp from Woodcraft(.https://www.woodcraft.com/products/pen-drilling-vise-w-7mm-drilling-guide-stop-collar-woodriver) Haven't invested in the press yet, since I'm just starting out. I'll keep that tip handy though for future reference.
 

LK&T

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The blowout is on the end I'm drilling, not the exit side. I use a drilling clamp from Woodcraft(.https://www.woodcraft.com/products/pen-drilling-vise-w-7mm-drilling-guide-stop-collar-woodriver) Haven't invested in the press yet, since I'm just starting out. I'll keep that tip handy though for future reference.
Blowout on entrance side is.....strange. My guess is that, even with the Woodriver guide, you got things cocked sideways a bit while drilling. I know you've invested fifty bucks in your guide, but you might want to look at getting what you need to drill on the lathe. IMO it's a much better method than using a hand drill and your guide, and I personally prefer it to a drill press (and I own a pretty nice drill press). It's also way cheaper than a drill press if you're not already set up to drill on the lathe. The downside is switching the setup from turning to drilling and back, but it only take a couple minutes. The upside is that making clean, perfectly centered holes is easy.

I square blanks with a reamer also, but I'm in the process of moving to a sanding jig. I have a Whiteside reamer, and they're supposed to be pretty good. And it is, as long as it's sharp. Once reamers go dull they cause problems. I've kept using mine because I sharpen tools for a living and have some spiffy tools for just such things, but if I didn't have an easy way to sharpen the reamer I would have given up on it before now.

A word on acrylics, resins and plastics in general. Everyone here's had to climb that hill and learn how to drill and turn this stuff. Way different than wood. I'm not gonna go into a big explanation because there's enough info on the site already to keep you reading for days. Plus, I'm not exactly "the authority" on how to do it. The expertise in this forum is extraordinary and lots of these folks are more than happy to help you out.
 
Joined
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Messages
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Location
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Blowout on entrance side is.....strange. My guess is that, even with the Woodriver guide, you got things cocked sideways a bit while drilling. I know you've invested fifty bucks in your guide, but you might want to look at getting what you need to drill on the lathe. IMO it's a much better method than using a hand drill and your guide, and I personally prefer it to a drill press (and I own a pretty nice drill press). It's also way cheaper than a drill press if you're not already set up to drill on the lathe. The downside is switching the setup from turning to drilling and back, but it only take a couple minutes. The upside is that making clean, perfectly centered holes is easy.

I square blanks with a reamer also, but I'm in the process of moving to a sanding jig. I have a Whiteside reamer, and they're supposed to be pretty good. And it is, as long as it's sharp. Once reamers go dull they cause problems. I've kept using mine because I sharpen tools for a living and have some spiffy tools for just such things, but if I didn't have an easy way to sharpen the reamer I would have given up on it before now.

A word on acrylics, resins and plastics in general. Everyone here's had to climb that hill and learn how to drill and turn this stuff. Way different than wood. I'm not gonna go into a big explanation because there's enough info on the site already to keep you reading for days. Plus, I'm not exactly "the authority" on how to do it. The expertise in this forum is extraordinary and lots of these folks are more than happy to help you out.
Ive been going through posts and gathering a lot of information and experiences, and have been learning quite a bit. I have been considering doing the drilling on the lathe, seems like that is a better option; that, and not having all that much room for a press.
After I initially posted, I found some videos on YouTube that "might" explain my issues:
1) I may not have had the glue completely covering the tube(especially at the ends) adequately, which didn't strengthen enough. It may have gone off a little as you said as well.
2) Probably the most important part. I didn't let the glue cure enough. CA glue and the activator set it, but i didn't wait long enough after (started the drilling within 5 minutes). I usually wait a few hours, but I was a bit impatient (go figure lol).
Lesson learned, that's for sure.
In the meantime, I have a few 7mm wood blanks ready to go for my next try, and will be trying again with the 3/8 (but a wood one).

As for the poly resin and acrylic, is there any difference in the method, or are they treated the same way? (as in drilling and turning).
 

leehljp

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If I run into problems drilling, I usually turn to something like this to get me started the next time:
unfurl="true"]https://www.amazon.com/dp/B01DU39UQ...jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==

And then, I up my speed and steady the blank by having a strong blank clamp. It is hard to figure out what caused the problems - drill bits dull, or not sharp, blank not held correctly or tight enough, or speed too slow, or entry too aggressive. Faster drill RPM does not mean that one can or should increase the feed rate. Keep the feed rate slow and deliberate.

Below is a picture of speed / RPM and the smoothness that comes with increased speeds vs chunks at slow speeds. BTW, it was done by an engineer friend.
 
Last edited:

LK&T

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Joined
Dec 1, 2020
Messages
139
Location
Sedro Woolley, WA
Ive been going through posts and gathering a lot of information and experiences, and have been learning quite a bit. I have been considering doing the drilling on the lathe, seems like that is a better option; that, and not having all that much room for a press.
After I initially posted, I found some videos on YouTube that "might" explain my issues:
1) I may not have had the glue completely covering the tube(especially at the ends) adequately, which didn't strengthen enough. It may have gone off a little as you said as well.
2) Probably the most important part. I didn't let the glue cure enough. CA glue and the activator set it, but i didn't wait long enough after (started the drilling within 5 minutes). I usually wait a few hours, but I was a bit impatient (go figure lol).
Lesson learned, that's for sure.
In the meantime, I have a few 7mm wood blanks ready to go for my next try, and will be trying again with the 3/8 (but a wood one).

As for the poly resin and acrylic, is there any difference in the method, or are they treated the same way? (as in drilling and turning).
The different plastics do feel different when turning, and some are definitely more brittle. When turning plastics I've learned that sharp tools are essential; way sharper than what's necessary for wood turning. I sharpen my skew and round nose scraper to 3000 grit, which is probably over the top but like I said I'm a professional sharpener and it's easy for me to go there. Somewhere around 1000 grit should get you good results. When you turn, take light cuts and don't try to hog off waste. Personally, I find a round nose scraper best at taking off most of the waste at a pretty good rate then switch to a skew for the last bit. Having said that, you're gonna blow up a few blanks. Everyone here has, and it seems to be part of the learning curve.

Drilling plastics is done slow. There's a couple stories on the forum from folks who've had a drill seize and break off in a blank because they drilled too fast. The drill gets hot and melts the plastic, the plastic gums up around the drill and causes it to seize. Most folks here recommend drilling at low lathe/drill press speed. I turn my lathe as slow as it'll go (500 rpm). Pull the drill often, clean off the chips and let the drill cool for a bit. The enemy here is the drill heating up and melting the blank as you drill. Happens quicker than you think. I go so far as to cool the drill with alcohol every time I pull it. Excessive heat will also oversize the hole.

Good luck and poke around old posts with the search function for more info. Then, post specific questions you have and folks will help you out.
 
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