Waxed fruit box mold ... need lining?

[chibi-soap]

Hi,
I made my first soap today. Woo hoo! I used a 1litre UHT milk container with a side cut off, but, since we don't usually drink milk from cartons, I thought I make this 15 minute mold...
https://www.soapqueen.com/bath-and-body-tutorials/tips-and-tricks/the-15-minute-soap-mold/

but rather than a sign, which I have no idea where one would get one from, I thought I'd use the waxed fruit boxes that are in plentiful supply at the greengrocers, something like this

but, since the cardboard is already waxed, do I have to line the mold?

ta muchly
chibi

 

[earlene]

Yes, you should line the mold with freezer paper (or parchment paper if you can't find freezer paper.)

It will make removal from the mold so much easier! I've used shoe boxes as molds and with the freezer paper I can re-use the box again and again.

Regarding the corrugated signs, you can also buy them at some office supply stores. But the box tops are generally free, so I like using them as curing trays (lined, of course.)

 

[Gerry]

Home Depot sells the blank corrugated plastic sheets they make those signs out of. It's dirt cheap, and made out of polypropylene (#5) so it's lye and dishwasher safe. At least here in Canada, it's sold under the trade name "Coroplast". You can cut it with any utility knife easily.

I use it for my mold dividers when I want to keep colors separate while pouring for doing swirls later after removing them - like a Mantra swirl for example. I even made dividers from it for my PVC tubes (which I also bought at Home Depot). They go into the dishwasher after each use and come out looking like new each time.

I don't use it for molds because it's a bit flimsy for my purposes, and making molds from cheap pine (also from Home Depot) is faster because the widths of combining 1x4 with a 1x5 make perfectly sized mold bars. No need to measure widths like you would with corrugated plastic. Even with a hand saw anyone could put together a wood one in about 15 minutes with a few nails because only 5 cuts are needed. Plus the 1" wood offers some insulation for those who want gel. And they last pretty much forever.

 

[chibi-soap]

Thanks Gerry. I hadn't thought about putting it in the dishwasher....but what about the tape?

A wooden mold would be nice, but I'm not so handy with a nail.

So a cardboard mold with a towel over it won't gel?

 

[Gerry]

Thanks Gerry. I hadn't thought about putting it in the dishwasher....but what about the tape?

A wooden mold would be nice, but I'm not so handy with a nail.

So a cardboard mold with a towel over it won't gel?

Insulated with towels will probably make it gel, provided of course that the mold isn't too tiny (like 1 bar). Just make sure you don't over-insulate and get your soap too hot once it gels. I'd lift the towel and feel the side of your mold now and then. If after a couple hours it isn't warm to the touch, add more insulation. If the side is really hot to the touch, lesson the insulation or remove the towel. This is low-tech thermal regulation. :mrgreen:

Keep in mind that higher soaping temperatures, and higher water and many additives including some fragrance oils will make things heat up faster, and vice-versa.

A taped together mold will be more problematic to keep clean no matter how you wash it. Likely after a couple of uses the edges will lift here and there, and old soap will get underneath. At least tape is cheap, and you can always re-tape it whenever it starts getting ratty.

 

[earlene]

So a cardboard mold with a towel over it won't gel?

Gerry answered already, but I can tell you my experience with cardboard molds.

I occasionally use cardboard boxes and even milk cartons (the waxed paperboard kind) as soap molds and I can definitely obtain gel. But when I do that I insulate well with towels and even sometimes wool blankets and/or cover with an upturned cardboard box to help hold in the heat. I also CPOP sometimes to facilitate gel, but it depends on the recipe and how cold my house happens to be in the winter.

I'd lift the towel and feel the side of your mold now and then. If after a couple hours it isn't warm to the touch, add more insulation. If the side is really hot to the touch, lesson the insulation or remove the towel. This is low-tech thermal regulation. :mrgreen:

I do that low-tech thermal regulation, too. :mrgreen:

A taped together mold will be more problematic to keep clean no matter how you wash it. Likely after a couple of uses the edges will lift here and there, and old soap will get underneath. At least tape is cheap, and you can always re-tape it whenever it starts getting ratty.

Regarding taping molds together, I really wouldn't recommend it. When I first started out, I taped together liners and after only a few times having to take them apart to clean them and then put new tape on them to get them back together again, I got tired of that whole process. Freezer paper is much easier to work with!

 

[SheLion]

Sorry for the hi-jack

I don't use it for molds because it's a bit flimsy for my purposes, and making molds from cheap pine (also from Home Depot) is faster because the widths of combining 1x4 with a 1x5 make perfectly sized mold bars. No need to measure widths like you would with corrugated plastic. Even with a hand saw anyone could put together a wood one in about 15 minutes with a few nails because only 5 cuts are needed. Plus the 1" wood offers some insulation for those who want gel. And they last pretty much forever.

Gerry, any chance you could post a picture of one of your 1x4, 1x5 molds? Is the 1x5 the bottom of the mold, and the 1x4s the sides? I'm having trouble visualizing it and can definitely fab up some of them once I have a picture. Thanks.

/thread hi-jack.

 

[Gerry]

Gerry, any chance you could post a picture of one of your 1x4, 1x5 molds? Is the 1x5 the bottom of the mold, and the 1x4s the sides? I'm having trouble visualizing it and can definitely fab up some of them once I have a picture. Thanks.

/thread hi-jack.

Funny you should ask, I posted a photo of my molds this morning in the Photo Gallery section.

The 1X4 is the bottom. The 1X5 pieces make up the sides that fit outside the bottom piece. The ends are 1X4. This means that my bars are 3 1/2 inches wide when cut the normal vertical way because 4" in lumber isn't really 4", but about 3.5".

I'll take a few more pics tomorrow and post them here for you.

 

[SheLion]

Gerry, I can look in the Photo Gallery section. And your description was also helpful as now I can see it in my head. But I'm still gonna check out the photos!

 

[Gerry]

Gerry, I can look in the Photo Gallery section. And your description was also helpful as now I can see it in my head. But I'm still gonna check out the photos!

Here's some pics. You can even see where I placed the nails. My molds are a little dirty... hahaha!

You need 3 pieces (3 cuts) of the 1X4, one for the bottom and one each for the ends. 2 pieces (2 cuts) of the 1X5, one for each side. Make them any length you like. Each of mine fit about 2kg of oils worth at 30 to 33% lye concentration with about an inch to spare at the top.

 

[chibi-soap]

Here 'tis. It's a bit daggy looking because I didn't take into account how thick the plastic is. I think the one at the top of this thread is made from thinner plastic. I might make another one that looks nicer. Wish I could have found a sign to make it for free but at least I can make a bunch of different shaped molds from the big piece I got. I was quite surprised that the soap didn't come streaming out.