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primus
Nov 19, 2007, 8:58 PM
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Ok, since I broke my hand in early September, I've had to have some sort of climbing-related outlet, so I built myself a climbing wall in my garage. I made a 50-degree overhanging section and picked up a set of Nicros HIT strips for training. For the rest of the wall, I've been making my own holds and am ready to cast my third set. I've been tweaking things each time, but am still not there. Here is the progression:
Round 1: I used floral foam (the wet type) to make the hold, then I used 100% silicone caulk to make the mold. For the hold material, I used a mixture of Bondo polyester fiberglass resin and some colored sand that I found at Hobby Lobby. I mixed it 60% sand and 40% resin by volume.
Result 1: The wet-type floral foam was really soft and difficult to work with; it also had such a fine surface that the holds that I cast came out really smooth--too smooth. I also didn’t take enough time to make sure that I applied the silicone so that there were no voids, bubbles, or other surface deformities, so the resulting holds had an uneven surface that needed to be ground down (which turned out even smoother than the rest of the hold!). The proportions of sand and resin seemed to be just fine, but the resin seemed to be somewhat slimy.
Round 2: I used a closed-cell green styrofoam that I picked up at Hobby Lobby. I thought this might work out better because there is so much more texture. Shaping the hold was not as easy. I used the same materials and techniques as Round 1 in terms of the silicone and resin/sand mixture, although I did a much more careful job of applying the silicone so as to try to eliminate the voids in the first round of holds.
Result 2: When I removed the styrofoam from the silicone mold I discovered that because the styrofoam was so porous, it actually tore away part of the silicone, leaving portions of the mold that were smooth. The resulting holds were, by and large, very aggressively textured (almost too much), but the sections where the silicone tore away left high spots and a very uneven surface. Again, the polyester resin after curing seemed slimy.
Round 3: I used the dry green floral sculpting foam to shape the holds; I found this to be the best material so far as it’s tough enough to withstand handling, but soft enough to be shaped easily. I tried to do a very careful job of applying the silicone to keep voids from forming and even went so far as to heat the silicone in hot water before application. After the silicone was applied, I smoothed it out and smeared it around with a plastic knife. When I removed the foam from the silicone mold, I was surprised to see that in spite of my efforts, there were still voids here and there—they were small voids, but voids nonetheless. I haven’t cast the holds yet, but I’m hoping for better texture than before.
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A couple of ideas that I’m planning on trying for Round 4: First, I’m going to try to dilute the silicone with a little bit of mineral spirits. I’ll then make a form in which I’ll place the hold and I’ll pour the silicone over the hold and let it cure—hopefully this will eliminate the problem I’ve been having with voids in the mold. I’m also doing this because it seems like pourable silicone is way more expensive than the 100% silicone you can get at the hardware store, so this may be a cheap alternative. Second, if the holds I cast this evening aren’t textured enough, I’m going to try taking a hard-bristle brush and rolling it over the foam to create texture. I think this’ll make a big difference, but we’ll see.
I’ve read on these forums that polyester resin tends to be slimy, but I’ve also read that some professional hold making companies use polyester resin, so I’m not sure what to think there. Is it Bondo resin that’s slimy, or polyester resin in general? Does anybody know how the professionals make their holds? Some people have posted that they have “inside” information and that they’d give the details in a PM, but I haven’t heard any replies yet, so I’m putting it out there. Anybody willing to share? Anybody got better ideas for hold material (polyurethane, etc.)? How about making the molds? Remember, I'm talking as inexpensive as possible!
Thanks!
(This post was edited by primus on Nov 20, 2007, 2:57 AM)
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northfacejmb
Nov 19, 2007, 10:01 PM
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Just after you take your hold out of the mold let it soak in some soapy water for a few hours. This should do away with the slimyness, at least it worked for me.
Make sure that the bolt holes are at a 90 degree angle with the back of the hold.
Also, don't make more holds than you need to get started. That way you can slowly by sets of holds and avoid having to spend lots of money just to get your wall started. Do not make all of the holds on your wall yourself. If you buy them you will get some better shapes and textures than you could ever do yourself before spending a fortune refining the delicate process of hold making.
Good luck with your holds.
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socalbolter
Nov 20, 2007, 3:37 AM
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Check at your local hobby shop (Hobby Lobby ?) and see if they have silicone mold kits. This will usually include a 2-part RTV type silicone that can be poured easily over your foam master.
This material will pick up better details than your silicone caulking and be easier overall to work with. It will cost a little more though.
You've settled on a foam that is very close to what most hold shapers use. The foams most commonly used are not really available (financially) to the general public without dropping the cash for a 4' x 8' sheet at whatever thickness you are looking to purchase. This is fine if you are doing a ton of commercial shaping, but not very practical for what you're describing.
By BONDO resin, I assume you are talking about BONDO brand polyester resin and not body filler paste (commonly referred to as BONDO). If so, what you are using will work fine, but is a low-grade resin and will be more brittle than other polyester resins that cost a little more. Again, probably not a real concern for the level you are operating at.
Polyurethanes will result in stronger holds, but the materials can be finnicky to work with and cost more.
Not sure what else you might be looking for, but I'll help where I can without divulging the specific secrets of any of the companies I work with.
Good luck with everything. Post some pics of your holds. This topic comes up often on this site and pics help people to understand better the results you are getting with your process.
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coastal_climber
Nov 20, 2007, 4:12 AM
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The problem is all the glue you've been sniffing, its probably not helping.
>Cam
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primus
Nov 21, 2007, 2:56 PM
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socalbolter wrote: Check at your local hobby shop (Hobby Lobby ?) and see if they have silicone mold kits. This will usually include a 2-part RTV type silicone that can be poured easily over your foam master. This material will pick up better details than your silicone caulking and be easier overall to work with. It will cost a little more though. You've settled on a foam that is very close to what most hold shapers use. The foams most commonly used are not really available (financially) to the general public without dropping the cash for a 4' x 8' sheet at whatever thickness you are looking to purchase. This is fine if you are doing a ton of commercial shaping, but not very practical for what you're describing. By BONDO resin, I assume you are talking about BONDO brand polyester resin and not body filler paste (commonly referred to as BONDO). If so, what you are using will work fine, but is a low-grade resin and will be more brittle than other polyester resins that cost a little more. Again, probably not a real concern for the level you are operating at. Polyurethanes will result in stronger holds, but the materials can be finicky to work with and cost more. Not sure what else you might be looking for, but I'll help where I can without divulging the specific secrets of any of the companies I work with. Good luck with everything. Post some pics of your holds. This topic comes up often on this site and pics help people to understand better the results you are getting with your process.
Cool--thanks for the info. I just got done casting "Round 3” and am happier with my results. Using the dry foam gave a much better texture and I scrubbed them in soapy water after they cured to try to wash some of the silicon mold release off, but they still feel a little slippery. Once again, there were a few surface imperfections that I had to grind down. I think I’ll give a try to adding more texture to the foam with a brush. Before I go buy 2-part silicone, I’ll also try adding mineral spirits to some silicone and pouring it that way. If the mold still turns out junky, then I’ll get some 2-part silicone.
I may have stumbled upon something while casting this last set though. After I cast the holds, I had a little extra material left over, so I poured it into the cap of the mold release can. I let it set up for just a little while and then I popped it out of the cap. It was all rubbery, so I decided to grind it down on the ground; the resulting hold tuned out to have really good texture! No silicone to make it slippery and the texture is a little more aggressive. Perhaps taking the holds out of the mold while they’re still curing and sanding them a little bit might also be a good way of adding texture.
I’ll post some pics of the different attempts at holds. They’re getting better and better; I think I’m about there.
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chris_23
Nov 21, 2007, 3:23 PM
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i dont know anything about making holds but the other day at the gym i saw a hold that just didnt look right and suddenly it came to me, it was half of a bottled water bottle...so i dunno if thats your problem(i dont really understand) but you could try making hold using everyday things for the molds
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primus
Nov 27, 2007, 4:16 PM
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Ok, I just finished casting my 4th set of holds using some older molds. This time I popped the holds out after about 20 minutes and I took them to the concrete. I roughed them up, took out all the high spots where the mold had voids and planed off the back so it was nice and flat (soooo much easier when they’re not fully cured!). Now that they’re cured, I’m impressed with the improvement in texture. No more greasiness and a rougher texture. The only problem is by grinding the holds down you end up altering the hold.
Round 5 is coming up soon; I just need to make it to Santa Fe to get some more sand (I may pick up some 2-part silicone while I’m there). I have three masters that I sculpted out of the green dry floral foam, but this time I took a stiff-bristled brush and pressed it into the surface of the foam over and over. I have a feeling that the resulting texture will be even better than I got by roughing the surface of the hold on the concrete. My only concern is getting all of the silicone mold-mold release off. (Any suggestions other than soapy water?)
I’ll post pictures as soon as I get a new camera…went climbing last Tuesday (first full-day out on real rock since I busted my hand in early September) and managed to crunch my camera pretty bad. The display is cracked, the body of the camera is all bent in, you can’t zoom or change any of the settings—it’s pretty much toasted. Also, once I figure out a solid technique for making holds that works well, I’ll post up a new thread with instructions and step-by-step pictures.
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fat_fists
Nov 27, 2007, 4:54 PM
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Primus,
I've made a number of holds myself. I've found that if you squeeze out silicon caulk into a metal or glass container you can thin the caulk with paint thinner. This makes the solution pour and fill the small voids of the foam.
BUT use a small amount of thinner, if you get it to thin it will dissolve the foam.
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undrtow218
Feb 2, 2011, 5:19 PM
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Hey, I have been trying to get my hands on some foam that would be ideal for shaping with a sander and some other tools, but I can't seem to find the kind of material that would work! I saw the "closed-cell" foam comment, and I can't find a distributor that sells it. I have been to my local hobby shop, and even went to hobby lobby.com, but still nothing. If you could send me a link or give me an idea of where to buy it, that would be great! Thanks!!
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clim.br
Mar 16, 2011, 6:19 PM
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kovacs69
Mar 16, 2011, 9:53 PM
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When I was making holds I used white sand picked up at builders supply shop. I also used this fiberglass colorant.
http://www.americanmarinesupply.com/.../coloring_agents.htm
I bought it someplace else at a cheaper price but a little goes a long way. I also found that some powder paint pigment worked well for coloring. Trial and error with the pigment.
I used this stuff to make the molds. It is very expensive but it works great. I would not have used this if I didn't work at Barlow's and got a significant discount. But again...it works great!
http://www.barlowstackle.com/...-Material-P1496.aspx
As for the slime. I used to put the holds in a bread crate and then power washed the hell out of them.
The only picture I could find fast.
Something to remember. You need to wear a good respirator when sanding fiberglass ( especially with sand / silica in it ) because the particles can get into your lungs and eventually cause lung problems including cancer.
Hope some of this helps.
Jon
(This post was edited by kovacs69 on Mar 16, 2011, 9:57 PM)
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