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Knife Making Discussions A place to discuss issues related to all aspects of the custom knifemaking community. |
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#1
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How tight is too tight? How cold is too cold?
Here is a question that I think the feedback will help a lot of new people (and I will more than likely learn something also):
When clamping handle material (scales) to the tang, how tight should the clamps squeeze? If you squeeze too tight, you squeeze out all of the epoxy and you do not get good adhesion. Clamp to loosely and you don't get good fit up. What clamps are being used, how many do you use and are you getting good results? I have gone both ways in the past, clamping too tightly and not clamping tight enough. Both result in gaps between handle materials and tang, or handle material coming off. What is everyone else doing? In addition, at what temperature do you attach handles? It is turning cold right now and not everyone has heated shops. Do you heat your materials and epoxy? Do you take it all into the house and assemble on the kitchen table? Do you do everything cold? |
#2
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Good topic Bob.
I have found some cheap "spring clamps" that produce just the right amount of pressure it seems. I get them at the local Dollar store. I use these when I'm pinning a handle. I have taken a few scales off and there has been a very consistent layer of epoxy left on the scale. I'd call it about .005" to .010" thick. I don't know if this is a good range, but it seems to work for me. Oh, I use 3 clamps, one on each end and one in the middle. As for temps, I try never to work with epoxy below 70 degrees. I have had a few problems with epoxy setting up and the common factor apeared to be temperature. In my past line of work I had to have some exopy flooring done. The pro's are very particular about the temperature at which they apply their epoxy. That about all I know about the subject. __________________ Eph 6:17.......the sword of the spirit, which is the Word of God: |
#3
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Bob,
I concur. I also use the cheap clamps with good success. I get mine from the local gun show. Usually there is someone there selling cheap Chinese/Taiwonese tools and will sell the plastic clamps for $.50. I use two sizes, small & medium and each has sufficient spring tension for a good glue joint. I have found that the most important thing on temperature with epoxy is the temperature of the glue at the time of using it. I will glue with it in a cold shop by warming the epoxy before use. The temperature during the curing doesn't appear to weaken the joint as much as lengthen the curing time. Gary |
#4
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Tapered or not, my tangs all have a hollow ground in them, for epoxy retention. I also use a 1/8"bullet point drill bit to make small depressions in the scales, for the same reason.
Edited to add; At this time of year, I take the knife inside the house to dry. It should be a minimum of 72 degrees for it to work properly. I keep my epoxy in the house year round, it lasts longer that way. __________________ Mike Last edited by Mike Hull; 12-09-2002 at 01:00 PM. |
#5
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I have been using Devcon 2 ton and it works well.
I will use 2 or 3 'C' clamps, depending one the size of the handle. Recently I have been drilling extra 1/8" holes through the tang and drilling matching 'pockets' in the scales about 1/8" deep to accept extra epoxy, this kinda makes an invisible epoxy pin for the scale to hold on to. The brass or silver pins I will fit a tiny bit loose and roll one end in epoxy before putting it into the handle hole, seems to put a film of epoxy on the pin. The clamps I put on go snug. I don't "crank" them till my hands hurt, but only till I think the glue is just about to stop squeezing out. Hope this helps. J. Hartt |
#6
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Bob - Hi from Calgary!!
I usually use the Devcon 2 ton. I rough the tang and bonding side of Dymondwood/whatever with 80 or 100 grit sandpaper to get a good roughed surface to get a good bond. I clean with acetone to get rid of any possibility of sawdust, oil, etc. I will use either those inexpesive clamps or small C clamps and use just enough pressure to have the epoxy start to ooze out. I use 3 clamps wherever possible. One at each end and one in the middle - in some instances only 2 if I have to work around pins. I check for fit and ensure there's an even amount all around. I tend to clamp fairly tight. I've found that you can clamp quite tight and still get the bond to hold. By quite tight, I mean once you wipe the overflow off, there's just a bit that will ooze out once it starts to cure. Just enough to maybe drip a bit past the tang. As it starts to cure, I clean up with acetone to save sanding it later. I cure at room temperature. I try to store my Devcon at room temp. When I worked with golf clubs, the epoxy I used was in a cooler place. What I did there, to loosen it up, was take a flat bottom bowl of some sort, fill it with hot water and put the epoxy bottles in and leave it for about 10 minutes. Works great. Hope this helps - gord __________________ Gordon Kamitomo Calgary, Alberta Canada |
#7
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Good answers. I like to bring up topics that I know the new people are not sure about.
I do mine a little different than some of the suggestions so far. After getting the materials flat, I takew one of those vibrating markers for marking your name on metal. I carefully go all the way around the tang and really carve it up. I stay about 1/16" inside the tang and then scribble all over the tang so that it is really covered well. I do the same to the handle material. I spread out my epoxy with a soldering brush nad make sure I get it all covered. I slide the handle material onto the tang, starting at the butt of the knife. This makes sure there are no air bubbles. Then I put one fairly strong clamp on that squeezes the center of the handle. After that clamp is on, I work from the butt of the knife towards the bolster/guard and put small clamps all around. I have been using "Binder Clips" that you use to clamp thick stacks of paper together. They come in various sizes and since they laid off half of my company I grabbed a bunch of all sizes before they hit the trash. I file rings around my handle pins and coat the inside of the hole as well as the pin before installing the pins. The only problem that I have is when I am finishing up the handle shape, I sometimes get a little too agressive and let it get hot. The epoxy lets loose at the hot spot and that is not easily reapirable and the handle has to come back off and start over. If I plan on installing handles, I put the epoxy, pins and the blades into a box I have that has a light bulb inside, just turn on the light and leave it on until the next day. Everything is at a good temp when I work it. Anyone else have suggestions???????????? |
#8
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How tight?
Bob, great discussion! You are right, threads like this help new people like me immensely. It also helps pass time until all the supplies/grinder comes in. Keep them coming. Bill.
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#9
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Bob,
Good point @ the temperature (& one I hadn't thought of) But, concerning the overheat of epoxy during final sanding, patience! (I can crow, it's my only real "skill" ) __________________ colin@britishblades.com
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#10
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Blow driers work great to warm everything up with before hand.
I warm the handle, tang, and glue before mixing. BTW, warming the glue makes it spread out thinner and bite better. I usually drill extra holes in the tang to allow the glue to work better, it bonds from side to side,though the tang. The cleaner, the better. I use acetone to clean everything before hand too. Mix epoxy gently, you don't want to agitate bubbles in the mix. Apply epoxy to all surfaces and squeese out the access. It may be messy, but it is SOLID! |
#11
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Geno - that's a good point!!!
Something else that I thought of that might be of help with cleanup. I think someone else actually mentioned this elsewhere, but in the Dollar Stores (Looney Stores in Canada!!) or the discount places, you can buy those really cheap plastic coasters. You can use these as a mixing base instead of a piece of cardboard or paper. Once the leftover dries, you can just flex the coaster a bit and the epoxy will break away enough that you can just peel it off. I usually mix with those round toothpicks or a popsicle stick and leave it on the coaster in the leftover epoxy by the knife or somewhere close (learned this when I was working with golf clubs). When the glue is dry on the coaster, it's probably dry on the club/knife. Just lift the stick and the epoxy will usually come with it. Hope this helps - gord __________________ Gordon Kamitomo Calgary, Alberta Canada |
#12
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i also groove both tang and slabs before glue up. it may have been bob egnath that suggested putting tiny pieces of notebook paper between the tang and the slabs. this keeps me from squeezing too much epoxy out of the joint using the plastic spring clamps from harbor freight. i keep the glue at room temp which is usually at least 65*.
__________________ wayne things get better with age ... i'm approaching magnificent |
#13
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I use the lids from coffee, peanut, and pringle cans for mixing surfaces, and do with them pretty much what Gord does.
I, like Doug, use the clothespin-type spring clamps (2 or 3, depending on handle size), and I definitely work indoors. Another thing I am meticulous about is cleaning all gluing surfaces with acetone bofre applying the glue. I use K&G epoxy, and Golfsmith's shafting epoxy. They both work equally well, but the latter is a bit easier to handle. |
#14
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When cleaning with acetone, what do you use?
Early on I used to use paper towels and the blue shop towels but they left lint. I have another way now, I clean them with cotton and then put the tang into a jar of acetone and let it set while I clean the other parts. I have my air hose ready and wipe the surface and blow it off immediately. This dries the acetone and blows off any lint that may be left. |
#15
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Another quick way to warm the epoxy, squeeze it out on your NON metallic mixing plate. Pop it in the microwave for 7-10 seconds, then mix it. I do this quite a bit in the winter.
I also wipe everything with acetone. I just use a white paper towel, give a wipe down each side of the tang, inside each handle slab, and all the pins. I have never had one come loose. Good paper towels wont leave lint. __________________ Mike |
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blade, fixed blade, knife, knives |
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