Cardboard box molds

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SoapAddict415

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Does anyone know if a good way to line a box mold? I can get 1-2 boxes from work that are the same size as the 1-lb silicone loaf molds I once had but I'd like to be able to use them more than once or twice.
 
You can use regular shopping bags if you want, but they're going to make wrinkly edges and the ink will probably transfer to the surface of the soap.

Or you can fold parchment or (better) freezer paper into a liner. It will probably leak a little bit from the corners unless you have a really stiff trace, but that shouldn't matter much.
 
I'd think it'd be similar to a wooden mold. As long as your cardboard is strong enough to support the soap and you can line with parchment or freezer paper well enough that you don't get leakage at the four bottom corners, you should be good.

You should make it your goal to use ONE piece of paper with the correct cuts and folds for the liner. This video gives a good description:

If you only use one piece of paper, your only possible leak points are the four corner points at the bottom of the box. If you do the three piece of paper method others teach (one piece for the length going up the sides and one more for each end, tucked under the first piece and going up the sides), you get full side corners as leak points which is not as good as four small points.

If you follow the video, your cardboard may not be strong enough for the rubber band to hold down the papaer - some tapes work, sometimes just a hard crease in the fold is enough to keep everything in place, and sometimes it's best to use a dab of removable mounting putty to hold the liner paper in place. Hope this helps.
 
Thanks BrewerGeorge and David1pro. Lol, I had a total brain lapse! We have thick tubing for making custom size bags. It's about 18" wide. I should be able to use a piece of that like I would use freezer paper. If I cut it at the seams, 1 piece would line 2 6x6x6 boxes. Thanks again!
 
I line cardboard boxes with freezer paper, same as with my wooden molds. Works fine. I usually only get leakage when I want intricate designs and need to stop pour at emulsion. So I double line them when that is the case.

More importantly, I found that transferring a cardboard box full of wet soap can be more difficult than a solid wooden mold, so I always put the empty lined box onto a heat-safe tray before pouring my soap. This way I can carry it to the oven for Oven Process or to another area where it will sit while setting up.

Edit: crossed out unintended word in 3rd sentence.
 
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I could never get Parchment paper to work well with out sticking and having to peel it. Freezer paper works the best but you need to cut it or get wrinkles. Any trash/grocery plastic bag will work but get the real thick outside bags, they are stronger :)
I would double check that the 'tubing' you have at work is. not sure if it is for making plastic bags ?

Also cardboard doesn't hold it's shape well unless it is one of those really thick kinds
 
I’ve used press and seal to line a cardboard box before. Doesn’t stick to the cardboard, or for lining a baking sheet, or really anything else I’ve tried. I don’t actually know what press and seal is actually supposed to adhere to except itself anymore. It’s kinda like Saran Wrap but thicker. It does give a nice texture if you can get it to work.
 
Press and seal you really have to press hard to make it stick to something. I had used that to line the inside of my cardboard tubes, had to really press hard. Then lined with Freezer paper before soap pour.
I now use it over plastic buckets when I get a bunch lined up with my oils all measured out in them. Then they are all set for a soaping day
 
I made a slab mold from cardboard and I painted the inside with FlexSeal paint. It made it smooth and waterproof then I just line it with parchment paper when I want to use it! Works great.
 
I've got a 6x6x6 cardboard shipping box so it's sturdy. We use a impulse sealer to seal the "tubing" ends to create a bag for larger parts. It's thick, I'm guessing it's 4 mil, like a contractor grade trash bag. It's been a few years but I used to use a type of cling wrap made by Glad to line my molds but I don't have any more and I can't remember the name of it. It was opaque and sticky on 1 side so it stayed it place and I didn't have a lot of the creases on the outside of my soap loaf like when I use plastic bags.
 
Does anyone know if a good way to line a box mold? I can get 1-2 boxes from work that are the same size as the 1-lb silicone loaf molds I once had but I'd like to be able to use them more than once or twice.
This is something i have experience in. I have mostly homemade molds. many wooden ones in diff sizes where sides come out or down. However, I have TWO that i grabbed up at a store once, so know what you're talking about.

the longest is 2.5 x 4.5 x 28 inches long cardboard box too! perfect for a large batch of tall and skinny soaps! I will share what i did and why. (sorry this is so long)

After cutting off the top flaps evenly, I duck taped it several times around the edges, the center, bottom, and every 6 inches, from one side to another to make it stronger, including around top edges where flaps use to be because it needs to be very secure. What I did is cut out a very thick industrial trash bag, only I allowed it to go over outside edges and down outside sides and bottom to protect the box completely, even on the outside. Cardboard is not strong many times to hold up for long periods of time against anything moist sitting in it much less weight of soap unless you add some forms of security to it. THEN, i still liner paper on inside just like the video above. I also tired a lone wire (jewelry wire) around the outside center, bending corners to shape... to keep it firm from bunkering; and twist wire together on one end. Duck tape has kept that from taring in the cardboard. Seems like more trouble this way, but then i have used the same box for very long time. These little efforts are worth it. hey if it works! lol
it actually is a great reusable mold! You can most likely also use a thick garden trash bag for an inner liner. I am just not sure if they are strong enough alone against the heat, not to melt. Another reason why i still line it with butcher type paper. if its smaller mold, and you have access to a large plastic store like grocery bags, you might could cut it so it's not as wrinkled, but i never tried that to see if it would melt but i know others say it works.
The tape, box, and underliner holds up well. Here is what they look like in raw form before lining. i keep flaps bent in the center, with a rubber band holding them together to keep it from bending when not using it.
 

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What I did is cut out a very thick industrial trash bag, only I allowed it to go over outside edges and down outside sides and bottom to protect the box completely, even on the outside. Cardboard is not strong many times to hold up for long periods of time against anything moist sitting in it much less weight of soap unless you add some forms of security to it. THEN, i still liner paper on inside just like the video above. I also tired a lone wire (jewelry wire) around the outside center, bending corners to shape... to keep it firm from bunkering; and twist wire together on one end. Duck tape has kept that from taring in the cardboard.

i love seeing homemade molds!
the industrial trashbag underliner- is that a permanant liner you've tacked down to the box or is that something that you take out after each use and replace?
does the wire support go all the way around the outer rim of the box or is it just around the middle to prevent the middle from bowing outwards? i'm trying to wrap my mind around it :D
 
sorry, was late..
No, i have not had to replace the thick trash liner nor the cardboard box to date.
i do replace the normal white butcher paper liner. like the video above is using. that is what i use to line them.
As far as the wire, i wrap it around the center, along with the outside, and when it meets up i twist it 2 or 3 times to hold it in place. mine are really long so they need that extra support.
However, you could just put something heavy like a couple of books on each side once your finished pouring. that would give it support as well.
 
I've got a 6x6x6 cardboard shipping box so it's sturdy. We use an impulse sealer to seal the "tubing" ends to create a bag for larger parts. It's thick, I'm guessing it's 4 mil, like a contractor grade trash bag. It's been a few years but I used to use a type of cling wrap made by Glad to line my molds but I don't have anymore and I can't remember the name of it. It was opaque and sticky on 1 side so it stayed it place and I didn't have a lot of the creases on the outside of my soap loaf like when I use plastic bags.

fruit boxes with lids if you can find them without holes and rim printing paper boxes that hold pks of 10, with lids are both very strong too and usually, the lids fit under box for extra support too. if you find the boxes that measure out so that you can make a few batches, but then that is one is ready to make much more soap. I have never used paper bags myself, afraid it will wrinkle up the soap to much but have heard some have done that. thats pretty thick. same as i used when i made my greenhouse. i think i put 6mm or something like that on it.
 
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