tylerd1994 Posted February 22, 2009 Report Share Posted February 22, 2009 Okay I know you can make a mold out of pop and rtv silicone. But i do not really like the pop molds all to well and the rtv is a little pricey. Is there any other alternatives I could use. Also is resin cheaper than rtv Quote Link to comment Share on other sites More sharing options...
bear21211 Posted February 22, 2009 Report Share Posted February 22, 2009 tylered the Bondo resin is fairly reasonable in price and you can pick it up at most auto parts stores or building supply stores. It does a pretty good job for 1 piece molds. Quote Link to comment Share on other sites More sharing options...
tylerd1994 Posted February 22, 2009 Author Report Share Posted February 22, 2009 okay i went to walmart and i looked at bondo but which one do i buy the only one that i saw that was called resin was fiber resin and resin gelly. could u tell me wat one to buy . also can you make a two piece mold out of it Quote Link to comment Share on other sites More sharing options...
tylerd1994 Posted February 23, 2009 Author Report Share Posted February 23, 2009 I am very confused about the resin. I looked at the posts and i know how to make one i just need to know what to buy. There is a bondo fiber resin thing at walmart for 10 bucks does that have everything i need in it Quote Link to comment Share on other sites More sharing options...
bear21211 Posted February 23, 2009 Report Share Posted February 23, 2009 you want the fiberglass resin tyler. if you buy the kit dont use the glass mat just resin and hardener. Quote Link to comment Share on other sites More sharing options...
Fish_N_Fool Posted February 23, 2009 Report Share Posted February 23, 2009 (edited) okay i went to walmart and i looked at bondo but which one do i buy the only one that i saw that was called resin was fiber resin and resin gelly. could u tell me wat one to buy . also can you make a two piece mold out of it tylerd1994 you can not make a 2 piece mold out of fiberglass resin as it warps from the heat as you pour and the plastic runs out the cracks. The only thing that works well is Durhams water putty. It is a dry mix you add water to like pop but you bake it in an oven at low heat to cure and it makes a super hard mold that is like bone. If you look here, there is a tutorial on making Durhams molds I believe still up. The only thing I have found better then Durhams for 2 piece molds is CNC machined aluminum. If you cant find a good tutorial let me know & I can help you out. Resin does make very good open molds because the warp doesn't effect them. FNF Edited February 23, 2009 by Fish_N_Fool Quote Link to comment Share on other sites More sharing options...
sagacious Posted February 23, 2009 Report Share Posted February 23, 2009 tylerd1994 you can not make a 2 piece mold out of fiberglass resin as it warps from the heat as you pour and the plastic runs out the cracks. The only thing that works well is Durhams water putty. ... FNF I wouldn't go quite that far. The only thing that limits Bondo as a mold material is the skill of the craftsman who makes the mold, or the ability of the one who uses it. Bondo works exceedingly well for two piece molds. My two-piece Bondo molds have poured countless baits, and I don't think they're likely to ever wear out. My Bondo two-piece molds never warp, regardless of how hot they get. Tylerd1994, you should start learning how to work with Bondo asap. It is suitable for a wide range of applications, and cost per mold is very low. Additionally, they won't crack or shatter if dropped, and do not require coating as plaster or water-putty does. These are significant benefits. Below is a mold I made to pour 8" curltyails for saltwater use. Hope this helps, good luck! sagacious Quote Link to comment Share on other sites More sharing options...
tylerd1994 Posted February 23, 2009 Author Report Share Posted February 23, 2009 Okay sounds good i may make one. So do you guys just use vaseline as your release betweent the two parts. Okay so i should be able to mix wat it tells me to on the box and be good to go. Quote Link to comment Share on other sites More sharing options...
Bassgrabber Posted February 23, 2009 Report Share Posted February 23, 2009 HI Tyler, Actually POP molds work well as long as you put the time into the preparation and finishing. I use them and my baits come out great. What I do after I pour the mold is: 1. Let the mold cure for 2 days 2. Lightly sand with really fine sand paper (300 grit) to knock out any imperfections and to smooth surface 3. Wipe out mold with tack cloth to remove all dust 4. Apply 10 - 12 light coats of high gloss polyurathane It will take you a week to get the mold ready to pour, but the baits will come out great. It's like anything else, the prep that you put into it will be worth it. Quote Link to comment Share on other sites More sharing options...
Vodkaman Posted February 23, 2009 Report Share Posted February 23, 2009 FNF is right, the mold does warp, at least mine did. The material seems to slightly soften with the heat. But this can be used to your advantage. By clamping as demonstrated in Sagacious's pics, this truly forms a good seal and I experienced zero flash, just the normal seam line, pouring lead ballast weights. I have the same clamps as Sag', but could not compress them far enough to use them, so I used a couple of G-clamps. I guess I need to do some grip exercises. What ever material you choose, there is a learning curve. You have to get to know the material, just like PoP, Durhams or RTV. It may take a couple of tries before you get the hang of it. Don't give up after the first attempt, learn from it. Dave Quote Link to comment Share on other sites More sharing options...
sagacious Posted February 24, 2009 Report Share Posted February 24, 2009 FNF is right, the mold does warp, at least mine did. The material seems to slightly soften with the heat. But this can be used to your advantage. By clamping as demonstrated in Sagacious's pics, this truly forms a good seal and I experienced zero flash, just the normal seam line, pouring lead ballast weights.I have the same clamps as Sag', but could not compress them far enough to use them, so I used a couple of G-clamps. I guess I need to do some grip exercises. What ever material you choose, there is a learning curve. You have to get to know the material, just like PoP, Durhams or RTV. It may take a couple of tries before you get the hang of it. Don't give up after the first attempt, learn from it. Dave Dave is right on about the learning curve. This is very much the same as when people make a crappy plaster mold and then say that plaster is no good. If your mold warped, blame the maker and not the material, and you'll get better results. Shortcuts will produce poor results. OK guys, I'll put out a few more tips that will make for perfect two-piece molds: First, I use Bondo Bodyfiller in the large 7lb can. There is no law that says one cannot place heavy steel wire within the mold-halves to reinforce a Bondo mold (like rebar in concrete). There is no law that says one cannot use woven steel screen within a Bondo mold to reinforce the mold. When I say that my molds don't warp, and will probably last forever-- I mean it. My molds cannot warp, because they were made correctly. A one-piece mold is usually made fairly thick. A two-piece mold often isn't-- see the problem here? A two-piece Bondo mold requires halves each at least 1" thick. Too thin causes problems. Economize too much and the mold may be useless. Two-piece Bondo molds must be clamped after they become firm, and during the entire time while curing, until they are room-temperature! Failure to clamp properly while curing may result in distortions later on! These molds should be stored with heavy rubber-bands around the halves to keep the proper alignment and prevent damage. There are many techniques and approaches to mold-making. Some of the above suggestions may seem old-hat, some may seem revolutionary. Really, when you sit down to make a mold, you're making a tool that should last a long time. One should take the necessary steps and acquire the necessary experience to ensure success before stating openly that a given technique doesn't work. To do otherwise is bad advice indeed. There's a world of difference between "It doesn't work" and "I couldn't get it to work for me." Bondo works very well for two-piece molds. The proof of the pudding is in the tasting-- and in the photos I posted above. If anyone wishes to post pics of their failed two-piece Bondo molds for us to see, I'll be happy to provide comments for improvement. Hope this helps, good luck! sagacious Quote Link to comment Share on other sites More sharing options...
Vodkaman Posted February 24, 2009 Report Share Posted February 24, 2009 WOW, great post Sagacious, many thanks for that information. I really like the 'rebar' idea, I will definately be trying that in my next mold. Dave Quote Link to comment Share on other sites More sharing options...
MTfishingrods Posted February 24, 2009 Report Share Posted February 24, 2009 And earlier I was half way through making a post that said dont do it. Thanks for the eye opener sagacious. I honostly thought that with what I had learned on here that it was not an option for 2 piece molds. In fact I had kind of scrapped it for even my one piece molds. Good post. You kick started the ol brain again. Quote Link to comment Share on other sites More sharing options...
GB GONE Posted February 24, 2009 Report Share Posted February 24, 2009 I would say try some hardened urethane. I have some molds made from this material and they are fairly indestructable and require no coating in the cavity. Here is a pic..... I did NOT make these molds so I am working on what material was used but will have info soon. I was told the material costs are low and easy to use. As said earlier, if you master the material, I am certain a 2 piece mold can be obtained. Jim Quote Link to comment Share on other sites More sharing options...
Romeo D Posted February 25, 2009 Report Share Posted February 25, 2009 Jim, Please keep us updated on the type of urethane as I am always looking to try something new. Also, Thanks for sending the mold out to me last week, I got it in a few days, it was a pleasure dealing with you. Romeo Quote Link to comment Share on other sites More sharing options...
GB GONE Posted February 25, 2009 Report Share Posted February 25, 2009 First, I use Bondo Bodyfiller in the large 7lb can. Two-piece Bondo molds must be clamped after they become firm, and during the entire time while curing, until they are room-temperature! Failure to clamp properly while curing may result in distortions later on! These molds should be stored with heavy rubber-bands around the halves to keep the proper alignment and prevent damage. Hope this helps, good luck! sagacious Can I ask what release agent you use between the mold halves when producing the mold? Jim Quote Link to comment Share on other sites More sharing options...
sagacious Posted February 25, 2009 Report Share Posted February 25, 2009 Can I ask what release agent you use between the mold halves when producing the mold?Jim Many things work. Depending on the specific application, I either use a silicone spray or a very light coat of vaseline. Bondo preserves enough detail to show fingerprints in the finished mold, so caution must be taken not to leave fingerprints in the vaseline mold-release. Vaseline is not suitable for some mold masters that have a lot of intricate detail. Silicone spray works very well as the solvent carrier evaporates and leaves only a very thin coat of silicone. Nothing sticks to silicone. Fine details are easily preserved this way. Another great way to prevent hassles with the initial mold-separation is to put a 1/4" strip of thin plastic shipping tape along the edge of the lower mold half before pouring the upper half. The tape should only cover 1/4" of the mold face edge, and be wrapped down over the outer mold edge. That way, after pouring the top half, and when you have to pry the halves apart, you'll have a thin tape line along the edges that will greatly assist in separating the mold halves without hassle. Once poured, remove the tape. Hope this helps, good luck. Quote Link to comment Share on other sites More sharing options...
Travis Posted February 25, 2009 Report Share Posted February 25, 2009 I have always used WD-40 with no problems for mold release for the bondo molds. I have always found bondo to make good molds as long as few precautions are taken and followed. With a drill press and indexing vise you can knock out simple molds in bondo stock easily. Quote Link to comment Share on other sites More sharing options...
Brad S Posted August 14, 2009 Report Share Posted August 14, 2009 Segacious Those are some nice looking molds and grubs. I made a 2 piece mold for grubs/curlytails out of p.o.p. with the sprue hole at the head of the bait like yours but when I poured some baits the plastisol would not flow all the way up to the end of the tail. Any suggestions? Thanks in advance. Brad Quote Link to comment Share on other sites More sharing options...
tylerd1994 Posted August 14, 2009 Author Report Share Posted August 14, 2009 brad, you have to pour the tail first while the mold is open , then put the mold together and pour the body. Quote Link to comment Share on other sites More sharing options...
Zbass Posted August 17, 2009 Report Share Posted August 17, 2009 I guess I need to go back to the drawing board. I have not yet been able to get what I call a good 2 piece mold form resin. Looks like you have mixed it with another compund of sorts because of the color sag. Maybe some body filler or something. I am gonna tinker around some more this fall and winter and see what I can come up with. Thanks for the inspiration. Quote Link to comment Share on other sites More sharing options...
Ed Brabant Posted August 17, 2009 Report Share Posted August 17, 2009 West marine has quite a few fillers for epoxy. Look at there web site www.westmarine.com and check out fiberglass fillers. I wonder if the fillers would help to prevent the warping by reducing the amount of resin. Does the resin alone have a shrink factor? Quote Link to comment Share on other sites More sharing options...
tauruck Posted August 20, 2009 Report Share Posted August 20, 2009 (edited) West marine has quite a few fillers for epoxy. Look at there web site www.westmarine.com and check out fiberglass fillers. I wonder if the fillers would help to prevent the warping by reducing the amount of resin. Does the resin alone have a shrink factor? The resin warps due to exotherm (heat). Depends on the depth, volume, size of container you're building the mold in. Polyester is the worst for this. Manufacturers specs say it shrinks between 2 and 5% depending on the conditions. Fillers are excellent at reducing/eliminating shrinkage and warping. Polyester being the cheaper option can be over catalysed if an accurate measuring system isn't used. Heavier fillers are best and marble chip comes to mind. Another way to eliminate the problems mentioned is to pour the mold in stages. This will reduce the high heat build up when the chemical reaction occurs. Just for interest sake, I've been making moulds from composites and Silicones for 30 years now and I would be glad to help the members with advice etc. Edited August 20, 2009 by tauruck Quote Link to comment Share on other sites More sharing options...
tauruck Posted August 20, 2009 Report Share Posted August 20, 2009 Just on the subject of release agents. PVA release agent can be used on any mould other POP. It's available from fibreglass suppliers and is cheap. Be warned it's water based. Quote Link to comment Share on other sites More sharing options...
Fish_N_Fool Posted August 20, 2009 Report Share Posted August 20, 2009 It is important to remember that Bondo body filler like sagacious is using and Bondo fiberglass resin are 2 totally differant matrails.Like I said earlier in this post fiberglass resins will warp with heat. Bondo body filler it sounds like does not warp although I have never used it. Fiberglass resin makes very good 1 piece mold though. I also use reinforcements in my molds for my Durhams molds I use a piece of 1/2" or 3/4" plywood with a bunch of holes drilled in it to stiffen and help keep Durhams molds from cracking. I just imbed in in the wet durhams then pour a little over it to encase it in the mold. This makes a very strong long lasting mold. I bake my Durhams mold at a low heat about 200 deg. for about 6 hours before coating them to seal the bait cavity. Quote Link to comment Share on other sites More sharing options...
