cranker Posted January 1, 2011 Report Share Posted January 1, 2011 I have a couple of do-it jig molds that came with the barb bait keeper molded into the mold.I do not like the barb style they use so I modified my molds and put my own style barb cavity in.The mold works fine and the mold modification worked like a charm so I would like to some way permanantly fill the factory barb cavity to prevent having to snip off the barb after pouring.Does anyone know of anything to use to patch out the barb cavity that would stay in the mold.The molds are aluminum of course but I am unaware of any products that one could use as a permanent fill and hold up to the heat of pouring hot lead. I know it could require sanding or filing to keep the mold closing smoothly,anyone know of any products for this or have any ideas? Quote Link to comment Share on other sites More sharing options...
cadman Posted January 1, 2011 Report Share Posted January 1, 2011 Cranker, Try 2 part JB Weld for steel. I don't believe they have one for aluminum. This will solve your problem. Also fill it on the high side as it will want to shrink as it hardens. Lightly file or sand with 600 grit sand paper. If you file, file slow and watch so you don't gouge your mold. It says it will withstand 300 degrees, which should be fine. Let us know how it works. Quote Link to comment Share on other sites More sharing options...
cranker Posted January 1, 2011 Author Report Share Posted January 1, 2011 Thanks Cadman,I will give that a try and let you know how it works.JB just may do the trick,I did'nt think about trying that. Quote Link to comment Share on other sites More sharing options...
JBlaze Posted January 2, 2011 Report Share Posted January 2, 2011 I have modified several of my molds, and JB Weld does a pretty good job. Here is a pic of one of them in the gallery. I think it would work well for what you are needing to do. John http://www.tackleunderground.com/community/gallery/image/7446-pic-of-modified-mold/ Quote Link to comment Share on other sites More sharing options...
psv Posted January 2, 2011 Report Share Posted January 2, 2011 Another vote for JB Weld. It works. Quote Link to comment Share on other sites More sharing options...
Hawkseyes Posted January 3, 2011 Report Share Posted January 3, 2011 How hard is JB weld? (rockwell? Hard-soft steel) What i'd like to do is use to fill and then rework by hand. Hawk Quote Link to comment Share on other sites More sharing options...
cadman Posted January 3, 2011 Report Share Posted January 3, 2011 (edited) How hard is JB weld? (rockwell? Hard-soft steel) What i'd like to do is use to fill and then rework by hand. Hawk I have never done a Rockwell hardness test on it. That is an intetresting question and a good one. I myself would like to know if it is machineable(spelling) after it cures with out cracking or breaking. I know you can re-work it by hand as I've done that, but I'd like info on machineability. I do know if you are going to make a permanent change it is best to weld the aluminum mold, and then machine it. This way you will never have a problem. Also I do know by welding it you will harden the surrounding area( from the heat of the arc in welding) which will make machining it more difficult. Definitely use carbide bits. I am going to try to get some insight from our resident super engineer Vodkaman. So what do you say V-man???? Edited January 3, 2011 by cadman Quote Link to comment Share on other sites More sharing options...
sdsaw Posted January 3, 2011 Report Share Posted January 3, 2011 How hard is JB weld? (rockwell? Hard-soft steel) What i'd like to do is use to fill and then rework by hand. Hawk Hand tools will work fine with it. They say you can sand, file, machine, drill and tap threads Quote Link to comment Share on other sites More sharing options...
sdsaw Posted January 3, 2011 Report Share Posted January 3, 2011 (edited) I myself would like to know if it is machinable after it cures with out cracking or breaking. I do know if you are going to make a permanent change it is best to weld the aluminum mold, and then machine it. This way you will never have a problem. Also I do know by welding it you will harden the surrounding area( from the heat of the arc in welding) which will make machining it more difficult. Definitely use carbide bits. Cadman, What I've experienced with JB weld is it is easily machinable. It does have a tendency to break if it gets thinned too much or on the sharp corners if struck. Another problem is with good adhesion to a flat surface if you place any kind of side load to the filler. I've had it get pulled out of a hole that I had filled in with it after a certain amount of pours (I may have allowed the mold to get too hot for it) It would help alot if you had deeper anchor holes for the filler to flow into and then harden. Optimum would be like how a dentist prepares a tooth for a filling when he's drilling where's the opening is smaller that the cavity itself. Welding aluminum will usually soften it because it will anneal the metal because of the heat. http://en.wikipedia.org/wiki/Annealing_%28metallurgy%29 Annealed aluminum is "gummy" and tends to load up or melt onto the tool bit. Carbide is not necessary, but a good cutting oil, slower tool and feed speeds prevent the tool from loading up. There's the mini lesson on machine shop for today Scott Edited January 3, 2011 by sdsaw Quote Link to comment Share on other sites More sharing options...
cadman Posted January 3, 2011 Report Share Posted January 3, 2011 Cadman, What I've experienced with JB weld is it is easily machinable. It does have a tendency to break if it gets thinned too much or on the sharp corners if struck. Another problem is with good adhesion to a flat surface if you place any kind of side load to the filler. I've had it get pulled out of a hole that I had filled in with it after a certain amount of pours (I may have allowed the mold to get too hot for it) It would help alot if you had deeper anchor holes for the filler to flow into and then harden. Optimum would be like how a dentist prepares a tooth for a filling when he's drilling where's the opening is smaller that the cavity itself. Welding aluminum will usually soften it because it will anneal the metal because of the heat. http://en.wikipedia.org/wiki/Annealing_%28metallurgy%29 Annealed aluminum is "gummy" and tends to load up or melt onto the tool bit. Carbide is not necessary, but a good cutting oil, slower tool and feed speeds prevent the tool from loading up. There's the mini lesson on machine shop for today Scott Scott, Thank you for correcting me. I have a lot of questions regarding welding aluminum but I don't want to hijack this thread, so I will PM you. Quote Link to comment Share on other sites More sharing options...
Hawkseyes Posted January 4, 2011 Report Share Posted January 4, 2011 Yea! I guess the best thing to do is take my mold to work and braze it with aluminum. Then I can mill and then do the hand work. Thanks Guys Hawk Quote Link to comment Share on other sites More sharing options...
Vodkaman Posted January 4, 2011 Report Share Posted January 4, 2011 I have never done a Rockwell hardness test on it. That is an intetresting question and a good one. I myself would like to know if it is machineable(spelling) after it cures with out cracking or breaking. I know you can re-work it by hand as I've done that, but I'd like info on machineability. I do know if you are going to make a permanent change it is best to weld the aluminum mold, and then machine it. This way you will never have a problem. Also I do know by welding it you will harden the surrounding area( from the heat of the arc in welding) which will make machining it more difficult. Definitely use carbide bits. Ted, I am a bit out of my depth with these questions, but here are my thoughts: JB weld – needs a rough surface to make a mechanical bond. If the bond surface is smooth, the JB will just chip off. If the ‘cut’ is made only just big enough and a smear of JB is used, the chances are that it will flake away. The cut needs to be larger and the surface roughed up. A 1/8” dremel router bit is good for this purpose, maybe the addition of a few shallow pin holes with a 1mm dia drill, 0.5mm deep is enough, don’t risk snapping the drill. Welding aluminium – I would be very nervous about this operation. Yes, some crystallization changes are going to occur around the welded area, but this is not going to affect the functionality of the mold. The changes could affect corrosion resistance as you are changing structure. My main concern would be permanent distortion of the mold mating surfaces, causing excess flashing. Another consideration is the make up of the aluminium used. It is almost certainly going to be an alloy of some description and may not be weld-able or at least difficult. May be worth talking to the mold supplier for his input on the material used, but don't expect him to give you the go-ahead for a welding op', you will have to research that viability question yourself. Dave Quote Link to comment Share on other sites More sharing options...
cranker Posted January 10, 2011 Author Report Share Posted January 10, 2011 O.K. guys,I used the JB Weld to fill the unwanted cavitys in my mold and wanted to report the results to maybe help some of you out.Bottom line is it worked perfectly! I mixed the two parts real good and let it set for maybe 10 minutes or so to let it get kind of gummy then applied into the unwanted areas of my mold cavity by dabbing it in with a toothpick.The toothpick allowed me to get a small gob at a time into the cavity without having allot of extra to clean out,it went in well and stayed where I built it up without any running or sagging.I then let it set up for about 24 hours which made it very hard which allowed me to gently sand it smooth so the mold would close properly and sanding was really easy as well.I have made several pours with no problems at all,the jb stayed in and seems to be holding very well.Also after reading the packaging it states that the cured product will withstand up to 600 deg. which is plenty for pouring hot lead without breaking down the weld.For mold repair and cavity filling this is the stuff to use but I dont know how well it would hold up for those wanting to do a major mold overhaul with it,it sets up great but is by no means truly as hard as steel like they state.It sands very easily but looks like it would be very brittle if you really went to doing serious machining on it.I do think after using the stuff and seeing how it reacts that one could actually use it to build a custom mold which may be my next project to try! People talk about making lead molds with plaster of paris and JB is much harder and more stable than plaster.Thanks for all the help with this and maybe my input on the actual results will help some of you out with similar needs. Quote Link to comment Share on other sites More sharing options...
