Brandon Miller Posted February 24, 2019 Posted February 24, 2019 What can be used for mold release if you don't have any spray mold release handy? Baby powder/corn starch that was suggested before did not work. Thanks in advance.
porschercr Posted February 24, 2019 Posted February 24, 2019 Cooking spray will work or petroleum jelly.
Ace-Garageguy Posted February 25, 2019 Posted February 25, 2019 (edited) Just buy the right stuff. The home-brews are marginal at best, and they don't work with everything anyway. Talcum powder, when it works at all, leaves a gritty surface. Vaseline has to be removed from crevices and indentations, and in the process it's easy to buff through it on high spots, leading to poor release. I've been making composite and "resin" parts for 50 years, and there's just no percentage in using something that's not designed for the job. Edited February 25, 2019 by Ace-Garageguy
Brandon Miller Posted February 26, 2019 Author Posted February 26, 2019 12 hours ago, Ace-Garageguy said: Just buy the right stuff. The home-brews are marginal at best, and they don't work with everything anyway. Talcum powder, when it works at all, leaves a gritty surface. Vaseline has to be removed from crevices and indentations, and in the process it's easy to buff through it on high spots, leading to poor release. I've been making composite and "resin" parts for 50 years, and there's just no percentage in using something that's not designed for the job. What mold release spray would you recommend?
Richard Bartrop Posted February 26, 2019 Posted February 26, 2019 Diluted dish soap seems to work well on silicone rubber.
SfanGoch Posted February 26, 2019 Posted February 26, 2019 17 hours ago, Brandon Miller said: What mold release spray would you recommend? Google it. there are a number of spray-on PVA (polyvinyl alcohol) mold release agents available, including in quart size bottles, which can be either brushed or sprayed onto the mold. You can also use regular hairspray in a pinch. The PVA/hairspray can be cleaned off the resin part by rinsing in water.
Ace-Garageguy Posted February 27, 2019 Posted February 27, 2019 (edited) 19 hours ago, Brandon Miller said: What mold release spray would you recommend? Depending on what material and process you're working with, there are several options. Here's a list from one VERY reputable and reliable supplier I've used frequently in the past. https://www.polytek.com/product-type/release-agents-sealers As SfanGoch says, PVA can be removed with water. It's a semi-universal release agent, but it has shortcomings in some applications. Some of the other release-agents are silicone based, and your parts will need to be thoroughly cleaned PRIOR to painting if you use one of them (isopropyl alcohol usually works). Edited February 27, 2019 by Ace-Garageguy
Ace-Garageguy Posted February 27, 2019 Posted February 27, 2019 I'm getting constant 404s and "can't edit comment" warnings when I try to add more material. Sorry...not my dog.
Aaronw Posted February 27, 2019 Posted February 27, 2019 Are you looking at mold release for resin casting? Not all resin / silicone require a mold release, so I'd check to see what is recommended by the supplier. If you are looking at something to keep the silicone from sticking when making a two part mold petroleum jelly (Vaseline) works fine. I've heard Pam cooking spray works, but never tried it.
Aaronw Posted February 27, 2019 Posted February 27, 2019 22 minutes ago, Ace-Garageguy said: I'm getting constant 404s and "can't edit comment" warnings when I try to add more material. Sorry...not my dog. I get that from time to time, it seems linked to the length of the post. I've found deleting a couple words will often let me post. It doesn't seem to be a too long post thing so mach as the software just not liking the specific length of the post if that makes sense (it only marginally makes sense to me as I type it).
Ace-Garageguy Posted February 27, 2019 Posted February 27, 2019 (edited) 2 hours ago, Aaronw said: I get that from time to time, it seems linked to the length of the post. I've found deleting a couple words will often let me post. It doesn't seem to be a too long post thing so mach as the software just not liking the specific length of the post if that makes sense (it only marginally makes sense to me as I type it). I've experienced the issue dozens of times. This time it was one sentence and a link. In the past, I've almost always found a way to post the information anyway, but I'm not going to bother trying workarounds anymore when there are problems. I've got enough to deal with in my own life without bending over backwards compensating for other stuff that's not my responsibility. Took me decades to realize there's just no point. Edited February 27, 2019 by Ace-Garageguy
GerN Posted February 28, 2019 Posted February 28, 2019 (edited) I've made a huge number (hundreds) of RTV molds (Permatex) using about a 70/30 mixture of mineral spirits and petroleum jelly on the object to be duplicated. I do let it dry before applying the RTV. This leaves a nice, thin, even coat of petroleum jelly on the master. This also works well as a mold release for poured resin, which I use if the mold has thin projections that might break. Edited February 28, 2019 by GerN
Brandon Miller Posted March 1, 2019 Author Posted March 1, 2019 On 2/25/2019 at 11:00 AM, Ace-Garageguy said: Just buy the right stuff. The home-brews are marginal at best, and they don't work with everything anyway. Talcum powder, when it works at all, leaves a gritty surface. Vaseline has to be removed from crevices and indentations, and in the process it's easy to buff through it on high spots, leading to poor release. I've been making composite and "resin" parts for 50 years, and there's just no percentage in using something that's not designed for the job. What mold release spray would you recommend?
Brandon Miller Posted March 1, 2019 Author Posted March 1, 2019 I'm using a 3D printed mold to cast resin parts so whatever release would be needed for that.
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now