mold question

[lavender.dreams.candles]

I have two wooden molds... 1 is a 2lb and the other is a 3lb.... well, I looked up the measurements of the 3lb and was wondering if I could find a pvc pipe that size would that make the same 3lb batch???
I know that is probably a stupid question, but, I'm going to go look tomorrow for a pvc pipe to use because I want to make goats milk w/luffa soap.

 

[Jamn!]

If you buy it a bit too big you can adjust it after you have your soap in there. I don't know the caluculation for volume but I think its in one of the stickies above.

 

[heartsong]

c

www.soapersmarket.com has both regular and round tube volume calculators.

 

[krissy]

Posted: Wed Mar 26, 2008 11:34 pm Post subject:
Basically, you simply multiply the volume of the mold by .40, regardless of the shape of the mold.

So, if the mold is cylindrical with the base radius of r and height of h, the formula would be: pi * r * r * h * .40, or about 1.257 * r * r * h.

If the mold is a half-sphere or a dome with radius r, the formula is: 2/3 * pi * r * r * r * .40, or about 0.829 * r * r * r.

Hopefully the math wasn't too confusing. Perhaps someone can explain it better than I can.

--Metal Substance

P.S. -- one way to figure out the volume of the mold is to fill it all the way with water, then pour the water into a measuring cup. Then, simply multiply the amount of water in the cup with .40 to get the amount of oil to use.


i copy and pasted this from one of the stickys is this what you are looking for?

 

[Inodoro Pereyra]

Krissy: you really confused me for a moment, to the point that I had to go read a little.
Your equation has an inaccuracy. The correct one for the volume of a cylinder is:

V= π x r2 x h

in which

π= 3.1415926
r2= base radius square, or r x r, as you correctly put it.
h= height.

There's not 0.4 multiplier in the formula. The volume is just the circle's surface ( π x r2) times the height.

So, to answer the initial question, if I read it correctly, if you have a mold with a square base, and you want to make a round mold which diameter is the same as the side of the square base, the area of your circle will be 78.539 % that of the square, which means that, for the same volume, your round pipe will have to be 1.27325 times the height of the square mold.

Now, the real question would be...Did I read the question correctly??? :?

 

[carebear]

actually the 0.4 IS a part of the calculation - if you are calculating the weight of oils to fill a mold. as krissy correctly stated.

now if she's talking MP soap instead then the conversion factor isn't necessary.

 

[lavender.dreams.candles]

ummm.... omgosh..... now I am really confused ..... all I wanted to know is if a round pvc mold is the same measurements as my wooden mold.
what size should I get the pvc pipe so it will make a 3lb batch??

 

[Inodoro Pereyra]

what size should I get the pvc pipe so it will make a 3lb batch??

What's the size of your mold, and what diameter pipe do you want to use?

 

[Milla]

And what's the diameter of your loofah? I haven't done loofah soaps but it looks like the pipe is usually the same diameter?????? Talking out of my a#$ here.

 

[lavender.dreams.candles]

my wooden mold is -
3.5 t x 2.5 w x 14 l

 

[Milla]

Someone please check my calcs. I just used the soap mold calc website.
http://soapersmarket.com/info_pages.php?pages_id=23?osCsid=ac85ebd78b30e0469812f24365d9267f

For a 3lb mold:

For a 2" diameter pipe you'd need a minimum of 41" length of pipe. Add more for clearance or if you are cutting it into separate pieces.

For a 3" diameter pipe you'd need about 18" for length plus clearance.

I've personally never used PVC. Last time I was at menards we had to buy a 6ft piece. It wasn't for soap though.

 

[Inodoro Pereyra]

my wooden mold is -
3.5 t x 2.5 w x 14 l

Your wooden mold has a volume = 122.5 in3

So, assuming you want to use a 3" diameter pipe, which seems to be very popular here, your pipe should be 17.33 inches tall.

Now, I don't have a clue what loofah is, so I don't really know what size it is. In case you need a different size pipe, the formula to know the height of your pipe would be:

H= Mv/ (π x r2).

Or H= 122.5 in3/ (3.1415926 x r2).

where H= pipe height, and Mv= wooden mold volume.

 

[carebear]

yes, about 18" of soap. (I got that 18" would get you just shy of 34 oz)

do not fill a 3" round mold more than 18" - way too unwieldy. trust me on this.

I actually find 12-15" much more manageable and even if it's a smaller batch, I personally think it worth the hassle of dealing with it.

Seriously, resize your recipe and do a 12" mold.

If you are using piece(s) of luffa they can take up significant space when all is said and done - so be careful.

And yes, PVC pipe is sold in 6 foot lengths. You can easily saw off chunks, though with a hack saw or reciprocating saw.

 

[Inodoro Pereyra]

Milla: you're about right. The height for the 2" pipe is 38.99 ", so it's close enough.

Last time I was at menards we had to buy a 6ft piece.

Ouch! :shock:

Go to Lowe's. They have 2 ft. pieces.

 

[Milla]

Milla: you're about right. The height for the 2" pipe is 38.99 ", so it's close enough.

Last time I was at menards we had to buy a 6ft piece.

Ouch! :shock:

Go to Lowe's. They have 2 ft. pieces.

I actually needed a 6ft piece so luckily I wasn't dooped! But thanks for the tip for 2 ft pieces at Lowes!

 

[carebear]

a 2" round soap that long will be even more challenging to get out of the mold... ask me how I know this stuff...

 

[Milla]

a 2" round soap that long will be even more challenging to get out of the mold... ask me how I know this stuff...

LOL! thanks for sharing all of your experiences!

 

[Inodoro Pereyra]

I actually needed a 6ft piece so luckily I wasn't dooped! But thanks for the tip for 2 ft pieces at Lowes!

You're welcome.