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Post by only87 on Feb 11, 2007 6:04:18 GMT 1
Naphtha, boys, naphtha. Get a suitable, quick seting, fast hardening (about 1 hour) silicone and then use the naptha method. Use the Hydroshrink maybe for reducing models bigger than 1/60 to somewhat between 1/72 and 1/87. Then use the naphtha method. This will end all your hit and miss experiments. Naphtha shrinking is perfectly predictable, in regard to scale and casting quality. Hydroshrink on the other hand is a pregnant dog. (preganant dog comes close but it's not what I wrote...)
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Post by superba on Feb 11, 2007 15:06:03 GMT 1
I am a little discouraged, but I can't turn back on the success I have had over the last three months. I am very close to my ultimate goal and will press on.
I was comparing the detail in the Lincoln Continental casting (a Dinky reduction) to the recently released Ricko Lincoln Continental. The reality is that my resin castings will not be slated for the back of the set...the detail is that good. My Lincoln casting actually has a grille.
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skunk
87thScale addict
5th B-day
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Post by skunk on Feb 11, 2007 15:24:58 GMT 1
Well, I am going to make some 1/43 shrinkings, because it seems that Hydroshrink works best when used in the recommended 1:4 proportion. But I also have quite a lot of six-hour silicone that has to be used before I start buying other kinds. I am assuming that "pregnant dog" originally began with the letter B?
But yes, naphta should also be fun to experiment with. I also want to try expanding some 1:100 models and such.
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skunk
87thScale addict
5th B-day
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Post by skunk on Feb 11, 2007 17:53:13 GMT 1
Maybe this should have been in the YouTube thread? ;D www.youtube.com/watch?v=Cp-i4qN7zqEIt's my Tomica Corolla shrinking, I took stills of the process and made a little short out of it.
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Post by only87 on Feb 11, 2007 18:28:27 GMT 1
I just wanted to say don't get discuraged, there is a solution for everything. I just don't think Hydroshrink is the one solution. When I tried the Hydroshrink, some projects worked out fine, others didn't. I tried to solve the problems I had with the stuff, but in the end I only pressed some projects, i. e. made molds of masters that hadn't cured to the end because the scale was already right. I just didn't want to do the same model over and over again until the master cures out perfectly. I was happy with the so-so results, but the next day I wasn't anymore. Then I got discuraged. The stuff wasn't as easy as it seemed first.
Lock the projects that bother you away for a month or two and work with the ones that turned out good. I have a Hydroshrink casting of a Tomytec Toyota Hiace, the grille and some other detail just didn't want to turn out satisfying. I redid the model with naptha and it turned out totally perfect. I was so happy that day, you can believe me, I sat there the whole day and compared both casting, and came to the conclusion that Hydroshrink just hadn't been the right stuff for this project.
I would say the Hydroshrink is the right stuff for the "raw" shrinking, I mean a basic reduction. The naphtha is perfect for controlled "scale corrections" If you use both methods together there will be nearly no dicuraging moments. Also the quality of your castings will increase.
Håkan, as you said, I would also use the Hydroshrink for 1/43 scale models first. I wouldn't experiment with smaller scales until you got some fine results with 1/43 (or around) models and are in the mood for experiments, not essentially results. Then work with the ones that turned out right. If you have some results that turned out too big, lock them away and forget them for a while and save them for a later day. If models turn out to small, toss'em in the litter box and forget them. Just don't press no projects. I wasted a lot of costy silicone until I got to that point.
If your done with the Hydroshrink, you can always pull out the projects that turned out too big and get some naphtha. And the fun begins again...
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Post by only87 on Feb 11, 2007 18:32:22 GMT 1
Maybe this should have been in the YouTube thread? ;D www.youtube.com/watch?v=Cp-i4qN7zqEIt's my Tomica Corolla shrinking, I took stills of the process and made a little short out of it. Nice! How did the Toyota turn out in the end?
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skunk
87thScale addict
5th B-day
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Post by skunk on Feb 11, 2007 19:12:36 GMT 1
That one ended up in 1:92, but very straight and true to proportions. I made another few attempts, we will see what my final results are.
If you guys make several Hydroshrink castings in the same mold, do you clean the mold in between? Because my latter efforts suffered some strange effects on the roof, hood and trunk - as if it had stuck to the mold there. I am going to clean the mold (soap, alcohol?) before recasting again.
If this problem is rather a result of too little water in the mix, perhaps letting it cure a little bit longer before removing the cast from the mold might solve it.
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Post by superba on Feb 11, 2007 19:29:06 GMT 1
Great Youtube display!!!!
I do clean out the mold. I just use water.
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Post by Cor_DutchArt on Mar 30, 2007 16:05:33 GMT 1
Maybe this should have been in the YouTube thread? ;D www.youtube.com/watch?v=Cp-i4qN7zqEIt's my Tomica Corolla shrinking, I took stills of the process and made a little short out of it. Hakan, I've seen a lot of reactions about this shrinking.. But, do you make a silicon mold in which you pour the hydroshrink or is it possible to make a mould of the hydroshrink to pour resin in?? As you know I'd like to give it a try too! Cor.
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Post by superba on Mar 31, 2007 0:01:14 GMT 1
I have made moulds out of Hydroshrink, then poured resin in after the mould has shrunk. Results: TOTAL FAILURE
The best approach ist to pour the hydroshrink in to an RTV mold. Instructions say you can remove the Hydroshrink casting after a 1/2 hour, but I have found its better to let it sit for several hours.
The Hydroshrink starts to shrink in the mold. If you pull out after a 1/2 hour sometimes the Hydroshrink breaks away at detail points.
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Post by Cor_DutchArt on Mar 31, 2007 18:14:15 GMT 1
I have made moulds out of Hydroshrink, then poured resin in after the mould has shrunk. Results: TOTAL FAILURE The best approach ist to pour the hydroshrink in to an RTV mold. Instructions say you can remove the Hydroshrink casting after a 1/2 hour, but I have found its better to let it sit for several hours. The Hydroshrink starts to shrink in the mold. If you pull out after a 1/2 hour sometimes the Hydroshrink breaks away at detail points. Joe, O.K. but what is exactly "RTV" Over here it means Radio and Television! Cor.
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Post by superba on Mar 31, 2007 18:48:45 GMT 1
Sorry for the acronym. RTV, latex rubber mold making material.
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Post by Cor_DutchArt on Mar 31, 2007 19:13:03 GMT 1
Sorry for the acronym. RTV, latex rubber mold making material. Thanks Joe!
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bjorn
Apprentice
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Post by bjorn on Apr 15, 2007 16:05:29 GMT 1
Dear All! (and especially Only 87) I´d like to learn more about the "naphta method". I´ve bought some 1:76 models from John Day and I will transfer them to HO, if possible. It´s a little bit difficult to get Hydroshrink in Sweden.
Best regards
Bjorn
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Post by Cor_DutchArt on Apr 15, 2007 16:31:29 GMT 1
Dear All! (and especially Only 87) I´d like to learn more about the "naphta method". I´ve bought some 1:76 models from John Day and I will transfer them to HO, if possible. It´s a little bit difficult to get Hydroshrink in Sweden. Best regards Bjorn Bjorn, Yeah I have the same problem here in the Netherlands. Those Hydroshrink people don't even answer my mails! Cor.
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