# How to Comb HDPE



## Can-Opener (May 11, 2013)

Here is a two part video on how to comb HDPE for a slingshot frame


----------



## Sherman (Oct 2, 2012)

Fantastic -- it really is a work of art! Thanks for putting this together for everyone. Makes an incredible slingshot. It would also make an insane psychedelic deck if you made enough of it.


----------



## Peter Recuas (Mar 6, 2014)

Thank you Sir, I'm waiting patiently on Christmas Day to begin using my oun oven


----------



## Arnisador78 (Apr 10, 2013)

Incredible!

Florida Forks


----------



## stej (Jan 16, 2013)

Those colors are beautiful. Every time I see some of your videos I remember my experience with HDPE - much more tough, stiff. So I also see how working with HDPE might look like 

Thanks for sharing, a lot of information is there.


----------



## jazz (May 15, 2012)

Hi Can-Opener, thank you very much!

jazz


----------



## derandy (Dec 28, 2014)

Realy beautiful. Now i want one ,made from Hdpe....


----------



## Chuck Daehler (Mar 17, 2015)

Can Opener's videos are always very educational, his willingness to share is exemplary.

I see a thicker more hand filling trend for HDPE coming.

I see two advantages of "combing" HDPE melts. 1. The "combing" effect also mixes up the lamination layers and the 2. remelt also aids in bonding it all together better.


----------



## leon13 (Oct 4, 2012)

thanks so much


----------



## Phoul Mouth (Jan 6, 2015)

I love these videos. About the scorching on the tops, I am pretty confident that is coming from that top coil in the oven. Have you tried making some kind of cover for the pan with a spacer to allow for air flow?


----------



## Can-Opener (May 11, 2013)

Phoul Mouth said:


> I love these videos. About the scorching on the tops, I am pretty confident that is coming from that top coil in the oven. Have you tried making some kind of cover for the pan with a spacer to allow for air flow?


It is not a problem since I have to plane off the air bubbles any way so I never worried about it. It only happens at the end and is also kind of an indicator for me to know when it is done  Thanks for the suggestion


----------



## Beanflip (Sep 11, 2010)

That's great Randy! You are mastering the material. Extremely helpful video. If I ever get back into giving this another shot your videos will be the definitive "how to" go to!


----------



## rockslinger (Nov 16, 2010)

Great video, thanks for sharing!

That shooter that you showed at the beginning is the cats meow! :thumbsup: :wub:


----------



## bigdh2000 (Feb 9, 2015)

Love the videos Randy.

During your first series of videos you mentioned leaving HDPE with a tool finish and using a buffing wheel to clean up any burs. However, I recently recall you mentioning or writing something about sanding HDPE as well. Care to elaborate? Just curious since I have done a little bit of this myself and have never been entirely happy with the results.

The rank and file of billets on the table for your kaleidoscope work cracked me up for some reason. Looks like you will be busy for a while. I assume you turned and cored all of them? What size and length do you need to achieve that size?


----------



## Teach (Jul 5, 2014)

Nice work CanOpener. I don't have a planer or jointer. Do you think the outer surfaces could be planed up with a jack plane? Or similar woodworking hand plane?


----------



## bigdh2000 (Feb 9, 2015)

Teach - I tried a hand plane myself just to see if it could be done. The results were not very good. I am not really sure how to describe what happened except to say that the blade got blocked very quickly and HDPE does not really peel back like wood. Something about the spinning blade in the planer prevents that from happening and does not require that the material peel back.

I did have reasonably good results with a hand held planer (about $25 at Harbor Freight Tools). The big problem is getting it flat and even. Better set up a jig of some sort as well to keep your slab from flying everywhere.

You can take the sanding route. Cut out your shape and then sand it to what you want, including the rough top surface. However, this is a lot of work since the sanding is almost like finishing up acrylic - down to the itty-bitty grits. YoullShootYourEyeOut (Matt) made a video about using a heat gun to bring back the shine once sanded. I have used a buffing wheel at about 2000 RPM to polish it up but after sanding the luster you get with the machining process (planer and router) just never seems to return.

You do not need a joiner. I never trim my edges. You just have to be careful that you do not hang your slingshot template over into the sloped side of your HDPE block. You can also run it through a table saw which I did on a really badly warped side once.


----------



## Chepo69 (May 1, 2010)

Muy ilustrativos tus videos Randy, gracias por compartir. Se ven geniales! Sí Gimy Hendrix hubiese usado resortera definitivamente sería una así.


----------



## Can-Opener (May 11, 2013)

bigdh2000 said:


> Love the videos Randy.
> 
> During your first series of videos you mentioned leaving HDPE with a tool finish and using a buffing wheel to clean up any burs. However, I recently recall you mentioning or writing something about sanding HDPE as well. Care to elaborate? Just curious since I have done a little bit of this myself and have never been entirely happy with the results.
> 
> The rank and file of billets on the table for your kaleidoscope work cracked me up for some reason. Looks like you will be busy for a while. I assume you turned and cored all of them? What size and length do you need to achieve that size?


When I first started messing with the HDPE I loved the fact that it did not need to be sanded and finished. As time went on I became less satisfied with the router and planner marks left on the frames. I always sanded and buffed the sharp edges from the start. Slowly I learned how to sand and buff the HDPE. Each mix is slightly different and color makes a difference also. But all of this aside It is very easy to buff and polish once you learn it. Takes about 15 minutes to put on an amazing finish that feels like polished Ivory in the hand. It is worth noting that a polished HDPE frame is not as slick as one that has not been polished. I have no rational explanation for this it seems like it would be more slick. The only thing I can figure out is the buffing compound is in a wax base so a coat of wax is applied as I buff. Makes me wonder if surf board wax is a possibility as a grip agent 

A short explanation of the sanding process.

I use a hand size 1/4 sheet random orbit sander

I use only 320 grit aluminum oxide sand paper

I buff at 1725 RPM this important and a 3450 rpm buffer will be very difficult to adapt to but not impossible 

I use blue buffing compound for plastic that I get from here http://www.delviesplastics.com/p/Buffing_Compound_PUC.html

I use a loose cotton wheel http://www.delviesplastics.com/p/Cloth_Buffing_Wheel.html

It takes a light touch and constant movement and very frequent charging of the wheel

I have had request for a video so I will happily be making one soon

Keep your latex out of the sun


----------



## bigdh2000 (Feb 9, 2015)

Can-Opener said:


> bigdh2000 said:
> 
> 
> > Love the videos Randy.
> ...


Your process is almost identical to mine. Only difference is that I run around 2200 RPM and an older wheel which I can change out. Time to try that polishing compound you use. With the stuff I have, the white seems to work a little better than the blue.

Have you had any issues with the sandpaper dusting/gumming up with use? I have to keep a separate/new sheet for the two color spectrum ends (dark vs. light colors). Also, after I sand, I wash the slingshot with Palmolive dish soap before polishing. It seems to do a good job of washing out/off any areas with the wrong dust color left behind before you push it in with the buffing wheel. Perhaps the de-greasing qualities are the helper here?

The ridges bugged me as well but I just did not like the lack of sheen I got after sanding no matter how much I polished. That being said, I have never really thought about trying a different brand of polishing compound. I have tried chrome polishing compound with limited success - I wouldn't advise/recommend it myself. Some candle wax was also tested - not much success there either. Note, all these tests were done with fresh loose cotton wheels.

The heat gun technique works well when you have the same type of HDPE. If you get two different melting rates you start having trouble with lumpy finishes with the heat gun.

...and yes, color is a major factor in my experience as well. The darker the HDPE, the less sheen you can bring out after sanding. Also, certain color dyes in the HDPE seem to change the melting rate. For me, the yellow buckets just do not melt well at all. Let me know your experiences.

Anyone tried beeswax on HDPE? My daughter (8) suggested high gloss clear lipstick. Perhaps I need to take her up on that idea. I do like the surf wax concept but be careful since some of the cheaper ones leave a cloudy finish on surf boards. Might do the same on HDPE.


----------



## Can-Opener (May 11, 2013)

Hope this is helpful


----------



## stej (Jan 16, 2013)

Btw. when I saw "sanding" I remembered my sand blasting experience.

I wasn't able to get a decent finish so I decided to try sand blasting. It worked on black PA6 very well, so I thought it might get similar results. Wrong! I didn't do it by myself as I don't have the equipment, so I ordered it locally (they sandblast different things, mainly to peel off paint). The result was horrible because they used little pellets (maybe steel pellets) that were already very dirty from previous session. Also the pellets were probably too big for my purpose, so slingshot was practically spoilt.


----------



## Can-Opener (May 11, 2013)

stej said:


> Btw. when I saw "sanding" I remembered my sand blasting experience.
> 
> I wasn't able to get a decent finish so I decided to try sand blasting. It worked on black PA6 very well, so I thought it might get similar results. Wrong! I didn't do it by myself as I don't have the equipment, so I ordered it locally (they sandblast different things, mainly to peel off paint). The result was horrible because they used little pellets (maybe steel pellets) that were already very dirty from previous session. Also the pellets were probably too big for my purpose, so slingshot was practically spoilt.


Too bad your sling was ruined  I have a sandblaster and I have blasted HDPE frames. It turns them frosty looking. I used clean sand by the way. I did not care for it but it did work. The frames did get dirty readily after being blasted  I usually make pinch grip style frame so the slick aspect dose not affect them as much. As I mentioned in the video I think the wax in the buffing compound gives them more tack.


----------



## bigdh2000 (Feb 9, 2015)

Can-Opener said:


> Hope this is helpful


Excellent video. Being that your wheel is a little larger than the one I use, the cotton is definitely a little looser. Time to sort that out and buy some of that wax too.


----------



## Teach (Jul 5, 2014)

bigdh2000 said:


> Teach - I tried a hand plane myself just to see if it could be done. The results were not very good. I am not really sure how to describe what happened except to say that the blade got blocked very quickly and HDPE does not really peel back like wood. Something about the spinning blade in the planer prevents that from happening and does not require that the material peel back.
> 
> I did have reasonably good results with a hand held planer (about $25 at Harbor Freight Tools). The big problem is getting it flat and even. Better set up a jig of some sort as well to keep your slab from flying everywhere.
> 
> ...


Dan is there a chance that you had the blade set too aggressively? ie to take too much material off rather than just a super thin shaving?


----------



## bigdh2000 (Feb 9, 2015)

Teach - I checked multiple blade depths. I have an old school Stanley plane with incremental adjustments.

Now I just pile a bunch of the blocks in the car and run down to my old man's house. He is retired and has plenty of time to run them through his planer.


----------



## Teach (Jul 5, 2014)

bigdh2000 said:


> Teach - I checked multiple blade depths. I have an old school Stanley plane with incremental adjustments.
> 
> Now I just pile a bunch of the blocks in the car and run down to my old man's house. He is retired and has plenty of time to run them through his planer.


Well load that puppy up and c'mon down to Mexico and we can run mine through too LOL. Randy offered to do this for me but said he didn't want to deny you the opportunity!!!!!!! LOL

I will maybe check with the local lumber yard and see if they could run it through a planer if they have one. So far I've not needed to do so......been sanding them yuck.


----------

