# HDPE or MICARTA Fork?



## Peter Recuas (Mar 6, 2014)

Greetings friends, I know this question is too broad but well wide is my dilemma, so if you are so kind please leave your quote from the point of view and depth you want, I thank you for your attention

Processes are in the public domain but what you prefer and why? are things I have to ask

Peter


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## Phoul Mouth (Jan 6, 2015)

I really can't recall seeing a slingshot made entirely out of micarta. Usually it is used as a laminate sandwiching an aluminum core, or as handle ornamentation. On the other hand we see slingshots made entirely out of HDPE all the time. I would probably say HDPE is likely the stronger material which is why it isn't usually used with an aluminum or wooden core.


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## Peter Recuas (Mar 6, 2014)

Phoul Mouth said:


> I really can't recall seeing a slingshot made entirely out of micarta. Usually it is used as a laminate sandwiching an aluminum core, or as handle ornamentation. On the other hand we see slingshots made entirely out of HDPE all the time. I would probably say HDPE is likely the stronger material which is why it isn't usually used with an aluminum or wooden core.


Thank you very much, question solved


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## Charles (Aug 26, 2010)

I strongly disagree. I have several frames that are made entirely from micarta. It is generally much stronger than HDPE of comparable thickness. Micarta is virtually indestructible.

Cheers .... Charles


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## Viper010 (Apr 21, 2012)

Micarta when well made is a "bulletproof" material, quite literally. Industrially, it was developed as light weight armor plating against small arms on vehicles. It's layered fabric, be it linen, burlap, fiberglass, carbon, twaron, Dacron, dyneema, Kevlar,...... Or a combination of two or more of those fiber materials, stacked, soaked in phenolic resin, and cured under pressure. As such it is very strong in deed. It will, however, sustain superficial cosmetic damage in case of fork hits with steel ammo. Repeated his in the sane area could create a soft spot where the busted up resin crumbles out from between the fibers.

This holds even more true for most homemade micartas, because the polyester resin most of us use simply isn't as hard as the industrial made autoclave cured phenolic.

All this being said, if you use a proven template, and properly home made micarta of, say, 8mm (3/8") thick, it would be impossible to get a catastrophic frame failure. Even with Jorg Sprave inspired band sets.

Now for hdpe... 
Although it doesn't look as sexy as micarta, this too is in slingshot applications nearly indestructible. I think, a hdpe frame of proven template, at 14mm (7/12") would likewise probably never fail catastrophicly (industrial board, I can't vouch for the integrity of homemade)

20mm thich (3/4") should experience no noticeable flex in proven template designs.

Fork hits on hdpe however, will only ever lead to superficial cosmetic damage, even a hundred hits in the same spot will only make slight dents but never will it create a soft or weak spot.

So... Short recap... Micarta has less flex and a sexier look to it. 
But hdpe will never sustain weak spots from impact.

So for lightweight, tacticool, custom work... Micarta, hands down. 
But for people new to slingshots... Hdpe all the way! 
You can never fork hit it so bad it has to be discarded.

Sorry for the rum fueled ramble guys
Hope I got all the typos????


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## Peter Recuas (Mar 6, 2014)

Charles said:


> I strongly disagree. I have several frames that are made entirely from micarta. It is generally much stronger than HDPE of comparable thickness. Micarta is virtually indestructible.
> 
> Cheers .... Charles





Viper010 said:


> Micarta when well made is a "bulletproof" material, quite literally. Industrially, it was developed as light weight armor plating against small arms on vehicles. It's layered fabric, be it linen, burlap, fiberglass, carbon, twaron, Dacron, dyneema, Kevlar,...... Or a combination of two or more of those fiber materials, stacked, soaked in phenolic resin, and cured under pressure. As such it is very strong in deed. It will, however, sustain superficial cosmetic damage in case of fork hits with steel ammo. Repeated his in the sane area could create a soft spot where the busted up resin crumbles out from between the fibers.
> 
> This holds even more true for most homemade micartas, because the polyester resin most of us use simply isn't as hard as the industrial made autoclave cured phenolic.
> 
> ...


Thank you very much Guys your advise have been very helpful, I like resins and their possibilities but was curious about hdpe (I never have worked it)

As you can see (local 02:30) I cannot sleep cause of my brain storm about, how to make a mould (not the square mould) to make a finished homemade pre moulded slingshot of (The winer) micarta . . . While reading your contributions occurred to me an idea of how to do this and now I'm so happy I can not sleep, I'll go get something to eat while downs :screwy: :screwy: :screwy:


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## Lacumo (Aug 18, 2013)

I put many winter Sundays into playing around with making my own HDPE boards at home out of HDPE pieces cut from milk jugs and liquid laundry detergent jugs. It's time-intensive, labor-intensive and doing it necessitates running your oven for quite some time. IMO, running the oven for hours probably more than offsets the "free materials"/"recycling is good" aspects of the process.

You can buy a 24"x24"x1" piece of HDPE via Ebay for >$70 and it'll yield around 2 dozen nearly bombproof slingshot frames. That's >$3 per frame. My experience with commercial HDPE boards is that they're unflawed and a pleasure to work with. When I cut them with a table saw, chop saw or bandsaw, shape them with a table router, belt sander or spindle sander or drill holes with a drill press, they produce less dust (with bigger particles) than wood or plywood. They cut and shape quickly and easily. If I make a fatal mistake in cutting or shaping a frame blank, I just lost ~$3. Not a tragedy like ruining some Pau Ferro, Redheart or Teak.

Micarta is definitely stronger and therefore superior in that regard. Nonetheless, the low cost and ease of working commercial HDPE are wonderful, the "almost no dust" aspect of working HDPE is great and the quality and durability of frames I can easily and quickly produce is marvelous. For a lazy, cheap guy like me, commercial HDPE boards are the best.


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## Chuck Daehler (Mar 17, 2015)

Here is my micarta manage. It is stronger than HDPE by far and works harder too... but HDPE is strong enough too...for slingshots anyway. Either will do you proud. Try both!
Link to pure micarta slingshots I made from blue jean denim and polyester resin:
http://slingshotforum.com/gallery/image/22574-goliath-magnum-gramps-knife-side-view/

Micarta was invented shortly after polyester resin was invented after WWII by G.E. to make circuit boards and other dielectric parts. G-10 is also micarta.c

I might add that when working micarta a very fine irritating dust emerges that necessitates a dust mask or damp cloth wrapped so it filters air you breathe. HDPE creates less dust and as the poster above said, larger particles at that.

Have you seen "starboard" at the builder supplies? That's HDPE as far as I know...someone correct me if not. It's less expensive than the $70 paid for a 24"x24"x1" panel as far as I know.

I melted all sorts of HDPE stuff cut into 1/2 or 3/4 inch chips to make three billets from which I made 6 slingshots. The electricity used by my toaster oven wasn't significant in cost at all. It took about 6 hours per billet too...slowly adding chips so as to avoid air bubbles.

One billet was swiss cheese full of bubbles. Evidently what I thought was HDPE was LDPE or something else and 170C bubbled it fiercely.

If you get bubbles, use a soldering iron and some HDPE dust collected/melted on the tip. Plunge the tip with melted pastic into the bubble and leave the blob of plastic there. Plunging it melts the surface to make a true weld, otherwise just smearing melted HDPE on HDPE will flake off.

Lots of videos on this, you'llshootyoureyeout is one of the maestros of HDPE on this forum...check his files.

While I liked the artsy craftsyness of making my own recycled HDPE billets and thence, slingshots, had I to do it over I'd either skip HDPE altogether or buy a sheet from USA AND have someone bring it down to monkeyland here in Ecuador. It's not bad to work with however, about the same as hard wood, wet sand instead of dry sand for faster better results. I sand down to 1200 then polish with automotive rubbing compound, finish with car wax. you can't get a brilliant shine, at least I couldn't, but a semi matt is fine for grip. But as the poster said, $70 makes oodles of slingshots so it's cheap at twice the price. A nice thick sheet of it gives you plenty of space to sculpt a super ergo. Here are a few of mine..
http://slingshotforum.com/gallery/album/1741-recycled-hdpe-projects/ however there are a number of forum members who have made a lot more than I have and have galleries of them.

Most HDPEs are simple board cuts from fused HDPE billets (some call them blanks) that are routed on the edges to radius them, a few holes drilled and groves cut.. and they are a whole lot simpler to make than a super ergo...yet give excellent fit and results. You might consider for banding cutting simple slots, faster, easier and less involved than mechanical clips and stuff. Just double the band over, stretch, insert in the slot with a match stick, piece of weed whacker nylon line or such in the loop to prevent it from slipping out.


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## Lacumo (Aug 18, 2013)

Starboard is HDPE with a UV inhibitor added into the liquid mix before boards are formed. It's intended for applications where the board will get extensive and extended exposure to direct sunlight, so the board will deteriorate more slowly and last longer. When you buy little remnant pieces (like 24"x24") from Ebay, pricing is "catch as catch can". I've bought some Starboard and some regular HDPE and the board foot prices were almost the same. At a materials cost of ~$3 per slingshot frame for 1" thick commercial HDPE, I'm not picky.

Those air pockets are why I prefer the commercial boards (plus I'm in the US, so I don't get clobbered with crazy intercontinental shipping charges). I'm on the doorstep of hitting 70, so SS frame failure under the stress of full draw and having broken SS frame pieces flying back into my face is my worst slingshot nightmare. I'm too old and fragile to suck up a shattered jaw or cheekbone like I could have back when I was young and invincible, so for me the commercial boards are a cheap form of high-quality insurance. The 1" thickness keeps things real safe, too...


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## peppermack (Dec 10, 2013)

I've made tons of frames entirely out of micarta. Love the stuff!


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## peppermack (Dec 10, 2013)

Sent from my iPhone using Tapatalk


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## Peter Recuas (Mar 6, 2014)

I found this photo of an old project on 2004, the seat of my recumbent bike was made with only two layers of towel and polyester resin (20% flexible+80% regular), bear my weight of 90 kg and pedaling efforts


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## bigdh2000 (Feb 9, 2015)

As has been mentioned above, slingshots can be made entirely from both materials. Making micarta is definitely more time consuming. It is also more expensive to acquire.

Most micarta slingshots are laminated in multiple layers of micarta. Generally speaking, 1" micarta is available but it does get hard to find much thicker than that. I have tried to go thicker but the clean layers start to deviate and the pot life on a lot of resins is not long enough.

I tried felt and was able to easily reach 1.5" but the lines/layers are not at all clean and I was struggling with the existing placed resin starting to go off before I had pressed it properly.

However, micarta is so easy to sand and polish. You can get a glass like finish on it if you have a buffing wheel.

HDPE is easy to make thick, but if you choose to deviate from more than a flat machined board cut, bringing back the shine is a huge chore.


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## peppermack (Dec 10, 2013)

I guess I'll should have stayed buy all my Micarta and it is commercial grade heavy duty stuff.

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## bigdh2000 (Feb 9, 2015)

After reading through everything again, I need to make one thing clear. I always make my HDPE and micarta in sheets after which I cut out the slingshot.


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## wll (Oct 4, 2014)

peppermack said:


> Sent from my iPhone using Tapatalk


I love those slingshots, nothing fancy, solid shooters.

wll


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## Peter Recuas (Mar 6, 2014)

peppermack said:


> I guess I'll should have stayed buy all my Micarta and it is commercial grade heavy duty stuff.
> 
> Sent from my iPhone using Tapatalk





bigdh2000 said:


> After reading through everything again, I need to make one thing clear. I always make my HDPE and micarta in sheets after which I cut out the slingshot.


Thanks guys, I completely understand, but you know. . . first I document me as much as I can and then I try to do things different way

Thanks a lot!


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## filipino_saltik (Oct 7, 2011)

micarta is not often used because it is a bit harder to work with than the hpde given you are using the same working tools.


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## mattwalt (Jan 5, 2017)

Phoul Mouth said:


> I really can't recall seeing a slingshot made entirely out of micarta. Usually it is used as a laminate sandwiching an aluminum core, or as handle ornamentation. On the other hand we see slingshots made entirely out of HDPE all the time. I would probably say HDPE is likely the stronger material which is why it isn't usually used with an aluminum or wooden core.


I use solid micarta or a derivative of for many of my frames. Works very well. Silk (paper) reinforced plastic. I find it works similar to a hard wood. Saws well, files well - but does take some time with the fine sandpaper.


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## vince4242 (Jan 11, 2016)

I made my own micarta and then made a slingshot out of it at 3/4 of an inch thick. Ridiculously strong and solid as a rock! Super easy to make all you need is epoxy layers of blue jeans and t-shirts like I made and put a heavy weight on it to compress it down until it dries. I made the micarta and it worked great and there's a lot of fun to make it yourself.


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