Polyurethane your molds? And bar weights.

[theBrewMeister]

I did a search on this and no one even answered the person asking the question so I'm going to give it a go.

Has anyone ever tried to polyurethane their wooden molds? Ive seen polyurethane liners sold for molds and I see a real potential here. I'm preparing to make some molds this week and have some poly on hand. Unless someone has tried it with no sucess Im definitely going to try it. gotta figure the worst thing that could happen is it not working and having to line the molds anyways. Worth a shot I think.

Next question, what do your bars weigh and whats their demensions?

I was looking on sunshine and found some inexpensive boxes for soap. I figure ill end up giving out a bunch as gifts and what not since Im making more than I could ever use, even if my whole family bathes 4 times a day. These boxes are 3,75" x 2.75" x 1.25" - anyone with bars this size? If so whats the weight? or Is there a formula for determining the weight of a bar given its size? I would assume that some oils are heavier than others but there has to be an average range.

 

[kommon_sense]

From what I've seen/calculated, it is pretty fair to assume 1 fl ounce is roughly the equivalent to 1 ounce by weight. So if you calculate the volume of the bar, that gets you very close to the weight of the bar.

Also, when in doubt, pour some fluid in a measuring cup and weigh it.

As for using poly, be sure to check its temperature range to make sure it will work for your needs.

 

[Sibi]

I did a search on this and no one even answered the person asking the question so I'm going to give it a go.

Has anyone ever tried to polyurethane their wooden molds? Ive seen polyurethane liners sold for molds and I see a real potential here. I'm preparing to make some molds this week and have some poly on hand. Unless someone has tried it with no sucess Im definitely going to try it. gotta figure the worst thing that could happen is it not working and having to line the molds anyways. Worth a shot I think.

Next question, what do your bars weigh and whats their demensions?

I was looking on sunshine and found some inexpensive boxes for soap. I figure ill end up giving out a bunch as gifts and what not since Im making more than I could ever use, even if my whole family bathes 4 times a day. These boxes are 3,75" x 2.75" x 1.25" - anyone with bars this size? If so whats the weight? or Is there a formula for determining the weight of a bar given its size? I would assume that some oils are heavier than others but there has to be an average range.

That's a really good question!! Does anyone have an answer or have they tried this?

 

[xyxoxy]

This may not help as I do round bars in a 3" PVC pipe mold. They are exactly 1 inch thick when I cut them and weigh (usually) approx 4.25 oz or between 120 and 130 grams. As they cure they get a bit lighter. I use a wet sponge to "polish" them which takes a little more weight off. Still they seem to stay comfortably at or above 4 ounces by the time I wrap them.

As for polyurethane... I can't say as I've never used wooden molds. I do recall a thread where donniej did some experiments with different wood sealers with the same idea in mind... not having to line the molds. I'm sure it should be easy to find or he may weigh in here.

 

[Deda]

I tried the poly on wood a few years ago. No joy. The soap stuck to the sides.

I'll never use anything but silicone, ever.

 

[Overthemoon]

Silicone is god, of soap molds. For me. Although my roommates mom borrowed my newest mold to bake a cake before she delivered me the mold. Ha. Shouldn't complain, she saves me a bundle on shipping.

 

[Deda]

I'd kill anyone who tried to bake in one of my molds. Scary, but true.

 

[Overthemoon]

And it's a WSP silicone mold too. Will make soap on my next free evening. I move Wed and then I'm in limbo with work so I really don't know when I'm coming or going.

They are trying to fire me and the shop stewards aren't making themselves available so no precedings can go forward. Bleh. I want to soap in my cake molested mold. Now.

 

[xyxoxy]

I'd kill anyone who tried to bake in one of my molds. Scary, but true.

I don't blame you a bit... I saw the pics of your soap kitchen with those priceless green WSP loaf molds that everyone is trying to get...

 

[Deda]

I'm retiring my little green molds and replacing them with Uplands block molds. (DH gives the best birthday presents)

 

[xyxoxy]

I'm sure you won't have any trouble getting rid of them. I don't know if WSP has any in yet but they can't seem to keep them in stock.

I'm very happy with my round hocky pucks and my PVC pipe molds but if I wanted to do loaves I would probably want those green molds.

 

[theBrewMeister]

Lmao, you guys hijacked my thread!

Anyways, I just made my molds lastnight and already have 4 coats of poly on them. The wood is almost saturated right now, so about 4 or 5 more coats might do the trick. What Im looking for is a smooth
non-porous surface. I think that if done properly theres no way it CANT work. Given enough coats of poly the surface becomes no different than that of the solid poly soap molds you buy. We'll see.

Ill keep it posted

 

[theBrewMeister]

UPDATE

Ok, so after 6 thick coats of polyurethane on fine pine molds, I poured a batch. Result, had to cut the soap out of the mold after 24hrs.

So, Im thinking I may need a better understanding of whats going on with the soap in the mold.

-Why will it not stick to freezer paper but it'll stick to tuperware?

Also, the soap still seemed rather soft, looked as if it was still 'gellin'.

-When's the best time to attempt unmolding?

I know you dont want to wait too long or the soap'll be hard to cut but I've also had issues with the soap pulling away with the freezer paper as well. So, im guessing that this is a sign that it was too early to remove, no?

Has anyone tried coating their molds with mineral oil? If so, what was your mold made out of and what were the results?

Sorry for so many questions but my books dont answer these

 

[dggriffi]

UPDATE

Ok, so after 6 thick coats of polyurethane on fine pine molds, I poured a batch. Result, had to cut the soap out of the mold after 24hrs.

So, Im thinking I may need a better understanding of whats going on with the soap in the mold.

-Why will it not stick to freezer paper but it'll stick to tuperware?

Also, the soap still seemed rather soft, looked as if it was still 'gellin'.

-When's the best time to attempt unmolding?

I know you dont want to wait too long or the soap'll be hard to cut but I've also had issues with the soap pulling away with the freezer paper as well. So, im guessing that this is a sign that it was too early to remove, no?

Has anyone tried coating their molds with mineral oil? If so, what was your mold made out of and what were the results?

Sorry for so many questions but my books dont answer these

freezer paper has wax on it.

To bad there isnt some way to coat your mold in teflon or silicon.

 

[dggriffi]

http://www.weberracing.net/p382/Aluminu ... _info.html

 

[Deda]

http://www.weberracing.net/p382/Aluminum-HT-Silicone-Spray-Coating-12oz-Spray-Can/product_info.html

http://www.docstoc.com/docs/28470484/MS ... ay---Black

 

[kommon_sense]

http://www.weberracing.net/p382/Aluminum-HT-Silicone-Spray-Coating-12oz-Spray-Can/product_info.html

I wouldn't recommend using that in contact with your soap. I would also think that you would have to reapply to the mold. Seems like introducing unnecessary chemicals into the mix starts to defeat the purpose of diy soap, especially when it is much cheaper/easier to get your hands on a roll of parchment/wax paper.

 

[kommon_sense]

UPDATE

Ok, so after 6 thick coats of polyurethane on fine pine molds, I poured a batch. Result, had to cut the soap out of the mold after 24hrs.

So, Im thinking I may need a better understanding of whats going on with the soap in the mold.

Can the poly take the heat? I would wonder of the poly melted and the outer layer of the soap/poly mixed. I wonder what chemicals leeched into your soap... Have you tried scraping all of the soap off part of your mold to see if the poly coating is still intact?

Gonna toss this idea out there. I haven't gotten around to trying it yet. I have a thin/sheet silicone baking mat that I got from bed bath & beyond a few years back. I don't see any reason why I can't cut it to line the mold to have a permanent liner and how have to worry about chemicals. I believe that I paid < $10 for the mat.

 

[theBrewMeister]

Polyurethane can handle temps of 176* F or 80* C. After cutting soap from mold i used water and sponge to remove soap residue and the poly was completely intact. there is no residual smell of poly on the soap either. Maybe using an acrylic now will do the trick.

Also, someone said that freezer paper was coated in wax. all the freezer paper Ive used or seen is coated in plastic.

I did a search and found that freezer paper is coated in Polyethylene- which is a polymer (plastic).

 

[xyxoxy]

I use flexible chopping mats cut down to size to line my PVC molds. I suppose if I were going to use loaf or similar molds I see no reason why I could not cut them to fit and permanently attach them to wood molds.

They are Polypropylene and can withstand as much heat as I've ever thrown at them... though I would probably hesitate to do CPOP with them. I've used them for HP and CP - both gelled and non-gel.