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Old 03-02-2019, 05:19 PM   #346
The Dark Side of Will
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Originally Posted by ghatid View Post
Here's the first version. I think I can get fewer bubbles in the next one, but probably there will be small imperfections on every set I make. I'm glad you guys are cool with figuring out the hardware yourselves.

In terms of materials, I have found something that is pretty hard (95 Shore A) and should be somewhat UV resistant. I want to beat up this version to make sure it won't get get ripped up when rocks hit it, but we can start with some photos.

https://imgur.com/a/c7H9SY5?

It's harder than the original, but it's still flexible so it should take rocks splashing against it. Anyone want to suggest some tests I can run in my garage or with basic tools? Like a drill powered mace or something?
Have you thought about trying a plastic welder to repair the crack in the original you're using as the pattern?

https://www.polyvance.com/Airless-Welders-1/5700HT/
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Old 03-08-2019, 05:37 AM   #347
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For removing bubbles, check out the technique used at 4:08 in this video:

https://www.youtube.com/watch?time_c...&v=WtodXHMDOP8
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Old 03-08-2019, 12:06 PM   #348
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Can you make a mold with something that can be molded? It is difficult to put into words but I was thinking if you made a mold with something that you could shape the way you wanted, like clay. Then you could make a mold of that perfected clay version.
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Old 03-08-2019, 10:31 PM   #349
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All great in theory, but I have never noticed any significant decrease in bubbles by the long path, small stream method. What's been working for the silicone mold has been using an additive that lowers the viscosity. Funny enough, I even ran a sander next to the mold to remove bubbles. Didn't realize that was a thing that other people did. What worked for the second silicone mold (much fewer bubbles around the BMW) was that after pouring, I just ran a screwdriver around the corners of the letters.

Aigar suggested, and the flap did well, until it didn't. Watch the video for more. I may have gotten too excited with the hammer, but I'll try to see if there are other castable materials as other options to try. Unfortunately, this stuff I was using poured really well and I was surprised at how few voids there are now that it's opened up. It's also UV stable which seems to be a hard spec to find for these castable resins; probably would be great for this application other than the fact that the flaps are going to be brittle while in the snow.

Any feedback on my tests would be great. This material does get brittle when it gets cold (my fridge is set to 0F), but maybe the hammer was too extreme of a test.

https://youtu.be/Gs2t_HvNaHc
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Old 03-09-2019, 10:25 AM   #350
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It says the video is unavailable.

For removing bubbles near the surface, use a heat gun or torch are sweep it across the surface. The heat will cause the bubbles to pop.

Instead of using resin, why not use a castable rubber?

https://www.smooth-on.com/products/vytaflex-60/

Something like that, although intended for making a mold, would potentially work very well.
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Old 03-09-2019, 12:03 PM   #351
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To remove bubbles from the silicon you should degaus(degass) the mixture, just put it in a vacuum chamber for a bit, then you can slowly pour the mold over something, and get exceptional detail for your mold. Maybe something with kydex sheets and vacuum forming that over a mold made from it, then trim it up with a router and your all set!
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Old 03-09-2019, 04:11 PM   #352
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Is it alright if I just ignore all 100 comments that are suggestions for removing bubbles? Yeah, I get it, if I had $20,000 worth of equipment or a $100,000 mold, I would make really nice parts. I'm just trying to get something that you bolt to the bottom of your car that stops mud from splashing up on to your car and looks pretty good from 2 feet away.

Maybe I focused too much on the bubbles when I showed you guys pictures, but they are at most 1mm-2mm wide.

Resin is just a generic term for chemicals that end up turning into polymers (read plastics) that you use to make things out of. @AndrewBird, you've given me the option of a urethane rubber (which is in the same class material as the thing I made the version 1 of the mudflap out of) with no UV resistance, about 1/3 the tensile strength, and the flexibility of a rubberband. It would just flap around in the wind and then eventually disintegrate unless you park it inside all the time. But, if you want, I can make a custom set with that material for you and you can test it out. Actually, in all seriousness, I 100% would not mind, but I don't want to run that test myself on my own dollar. I would love to be proved wrong and these molds would work with that material no problem.

I hope I'm not coming off as too impatient, but Jesus Christ guys. You've been waiting for something like this for years. The last set went for $700. Wouldn't you like a not-perfect one for $100? I am asking you guys questions not because I don't know what I'm doing, but because I want to get an idea of what you guys are expecting and I want you guys to have realistic expectations of what I am able to make in my garage with limited resources. I think I have enough info from you all. I'll re-update when I've made a few sets and finalize pricing. Then I'll ship some over to the guy who lent me the flap and he can give an independent review of them (if he's up for it).
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Old 03-10-2019, 11:52 PM   #353
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In all honesty, when I first saw these I imagined them flapping around with the wind the faster I went. Such a great idea. It would shed mud automatically. Count me in on the urethane set! Also, I'm sure everyone here has good intentions when offering advice, but that last string of replies was kind of ridiculous.
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Old 03-11-2019, 07:27 AM   #354
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lol, what, you don't have your own vacuum chamber in your garage?
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Old 03-11-2019, 11:05 PM   #355
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Originally Posted by ghatid View Post
Is it alright if I just ignore all 100 comments that are suggestions for removing bubbles? Yeah, I get it, if I had $20,000 worth of equipment or a $100,000 mold, I would make really nice parts. I'm just trying to get something that you bolt to the bottom of your car that stops mud from splashing up on to your car and looks pretty good from 2 feet away.

Maybe I focused too much on the bubbles when I showed you guys pictures, but they are at most 1mm-2mm wide.

Resin is just a generic term for chemicals that end up turning into polymers (read plastics) that you use to make things out of. @AndrewBird, you've given me the option of a urethane rubber (which is in the same class material as the thing I made the version 1 of the mudflap out of) with no UV resistance, about 1/3 the tensile strength, and the flexibility of a rubberband. It would just flap around in the wind and then eventually disintegrate unless you park it inside all the time. But, if you want, I can make a custom set with that material for you and you can test it out. Actually, in all seriousness, I 100% would not mind, but I don't want to run that test myself on my own dollar. I would love to be proved wrong and these molds would work with that material no problem.

I hope I'm not coming off as too impatient, but Jesus Christ guys. You've been waiting for something like this for years. The last set went for $700. Wouldn't you like a not-perfect one for $100? I am asking you guys questions not because I don't know what I'm doing, but because I want to get an idea of what you guys are expecting and I want you guys to have realistic expectations of what I am able to make in my garage with limited resources. I think I have enough info from you all. I'll re-update when I've made a few sets and finalize pricing. Then I'll ship some over to the guy who lent me the flap and he can give an independent review of them (if he's up for it).
Chill man. You are taking helpful advice as criticism when everyone here wants to see this happen.

When you said resin, I thought of typical casting resins which are closer to plastic than rubber. You even said it was brittle when cold. You said the material you are using is 95A so I suggested a type of product that was 60A. I wasn't being specific, merely showing you there are other options. You said yourself you don't know what you are doing. I was leaving it up to you to find one that fits your needs.

You seemed worried about the bubbles so several people (including myself) gave some solutions. We are trying to help, not nit-pick your work.

P.S. - You can get a vacuum pump and small chamber off amazon for less than $300. Not exactly breaking the bank when you are considering selling these for several hundred.

https://www.amazon.com/Value-Gallon-...-2-spons&psc=1

Keep up the good work!
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Old 03-12-2019, 07:06 AM   #356
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What is this, a vacuum chamber for ants?!
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Old 03-14-2019, 03:03 AM   #357
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What is this, a vacuum chamber for ants?!
It's 3 gallons in size, plenty big enough for a tub of resin to fit in.
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