Custom Fitted Gel Insoles




About: I'm that guy from that place who built those things

Here is how to make fitted gel insole made just for your unique feet, for about 20 bucks.  fitted orthotics are about 300 bucks


1 pair of your socks
2 tubes silicone caulking (a pack of 3 tubes was 10 bucks from a hardware store, you may need more is your feet are bigger then mine.  I'm a size 9.5 mens)
1 small bottle of glycerine (5 bucks from a pharmacy, this will do about 3 or 4 pairs)
caulking gun (5 bucks from a hardware store)
a cardboard box
1 old spatula or paint stir stick

your hands and feet will get a little bit sticky

note the caulking will smell strong like vinegar but it should be non-toxic, if the smell bothers you, move to a better ventilated area

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Step 1: Silicone Caulking Set Up

1st step.

squirt out all the silicone caulking from one tube on to a piece of cardboard. one tube will do one insole.  If you feet are bigger than a mens 9.5 you might need to add another half a tube.

2nd step.

add about 5 drops of glycerine for every ounce of caulking (if you dont add the glycerine the silicone will not cure all the way through and you will have a cured surface but a uncured middle) and mix thoroughly with spatula.

the warmer your work space the quicker the cure time but you should have about a 20 min window before its starts to cure.

Step 2: Setting Up the Moulding

3rd step.

turn inside the socks and put one on your hand.  scoop up the caulking (like a snow ball)

4th step

Now carefully turn the sock right side out and try to keep all the caulking at the sole of the sock

5th step
squish the sock to even out the caulking and even out the sock material ( if you dont even out the sock material you might get folds set in, which might be uncomfortable)

make sure you spread it out enough for you foot size and make sure most of the caulking is at the heal and arch areas.

and repeat for other sock

Step 3: Molding Your Feet

6th step

place socks on a piece of cardboard, wait a few minutes for the caulking to start to firm up a little bit. 

now step on the socks so your foot is centered and keep your feet in position for a few minutes.

7th step

now carefully remove your feet.  (your feet might stick)
if the caulking is not holding the shape of your foot, you might need to massage the caulking back into place and retry

make sure to wipe off your feet good before walking around, the glycerine or caulking might make your feet slippery

UPDATE.  I'm going to try placing a piece of plastic wrap or a shopping bag, on top of the insoles.  so when I mold my feet, my feet will not stick to the insole.  After it starts to set, gently peel off the plastic.

Step 4: Curing the Silicone Caulking

now just put in a warm ventilated place to cure.  it might take a day or 2.

Step 5: Trimming to Fit

note before you start trimming, make sure its cured

now center your old insole over the new and trace it out.  trim off excess material with some scissors.

now you have it cut to the right size you will have to slightly tapper the sides so the bottom will be just a little bit narrower then the top.  this is so it will fit better in the shoe.

now you will put the sole in your shoe or boot and see how it fits.  you might have to take it out and fine tune it by removing a little bit of material.

Step 6: Conclusion

now you have insole fitted for your feet for only 20 dollars

mine feel and fit awesome. 

I've had these in my work boots for almost 2 months,  these feel so great.  My feet are very happy



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    27 Discussions


    10 days ago

    I read some of the other comments, on curing and the odor. Might be a good summer time project, where to cure them, to put them inside your car parked in the sun. Or if in winter, place over your heater from furnace, or onto radiator, however you heat your home. That the heat will help cure, but in any case, the silicon must cure. Once cured, most of the odor will stop. If not cured, then odor remains noticeable. But it must be cured, to keep the integrity of fitting your foot. A project well worth the effort for shoe soles that fit your foot to get happy feet.
    Also, to not have toes in the final product, I would recommend that your foot has socks on them, and will give you a smoothed out toe area, where when you use them, that wearing socks will have better fit. Something that you use for your best use, using your own best beliefs of what works best for you.


    3 months ago on Step 2

    Awesome, i’ve actually been wondering if it would work to make inserts with silicone. Thanks for this instructable. If you ever do a video I would love to see it!


    1 year ago

    Thank you! Might the silicone be slightly toxic, if pressed on constantly with skin?

    Also, will the slightly acidic silicone damage nylon socks?


    5 years ago on Introduction

    Use Red Devil caulk, not GE. GE takes longer to cure and is harder, not as flexible.
    For extremely high arch, make a plaster model. Use an old shoe box for a cope. When plaster starts to set, insert greased foot deep enough to make a good impression. Slit the impression down the center before it hardens. When hard, grease the impression and fill it with plaster.

    Spray the plaster positive with Cyclo Silicone spray or another brand that is not full of grease or Kerosene. Apply silicone mix with a putty knife. Cosmetic tube caps can be used to make relief cavities for metatarsal heads if needed,.

    Nine drops of glycerine per oz. will produce a firm set in about three days, but outgassing will continue for a week or two.

    Next project: adding full contact arch support to inexpensive Rexall Drug silicone insoles for shoes with insufficient toe box depth. My feet are so cavous that commerialy available custom orthotics will not work. My ulcer is finally closed for business.

    4 replies

    Reply 2 years ago

    Wow. Thanks for the very detailed, helpful response. :) You made my day. :)


    Reply 2 years ago

    Okay. I have an extremely high arch due to nerve damage, and absolutely need to make this if I want to walk without discomfort.

    Clarification on your steps:

    1. Insert Greased Foot. What do I use to grease my foot?

    2. Slit the impression down the center. This is is so you can easily break the mold off the finished product, correct?

    3. Grease the impression. Again, what should I use to grease it?


    Reply 2 years ago

    1. Vaseline. Queen Helene's Cocoa Butter Creme may be better for the foot, Vaseline for the mold. Do not forget toe nails!

    2.0therwise removal would be impossible!

    3.CRC Silicone spray & Vaseline. The entire contact surface must be coated. Same for the model before applying the caulking compound.


    Reply 2 years ago

    1. I used Vaseline, forgot to put some under my toenails. Queen Helene's Cocoa Butter Cream may be easier to remove afterwards.
    2. Yes, otherwise there would be no way to remove the casting.
    3. I sprayed mine with CRC Silicone and followed up with Vaseline. Once the casting is dry and prepared, use the same products to facilitate removal of the silicone. I found a Dr. Comfort shoe horn to be the best tool to facilitate peeling the silicone from the plaster.

    It is necessary to get the soles equal in thickness. I drilled and tapped four holes in the castings and inserted bolts, adjusting them for 1/4" clearance from a flat surface. Then I built up the caulking compound to the top of the bolt heads. The plaster would not take threads, so I used JBWeld to hold the bolts in place.

    Note: I have hammer toes, so I need extra depth in the toe box, Dr. Comfort's Brian X is the only shoe I can find.

    Alternate mold method: search on line for a foam impression kit, probably about $25.00 + freight. Much less plaster mess that way.

    Alternate sole: Rexall's silicone orthotics: fill the arch & midfoot of the model with caulk, then place on the insole to cure. Floppy and tricky to insert in the shoe but comfortable enough to walk a mile in Old Mill boots that are not roomy enough for the thicker home made soles.


    3 years ago

    I made a set of these yesterday. 2nd set turned out great! Apparently with my first try, I used caulk that was not 100% silicone - never set up. 2nd set cured quickly. I made them just a bit too thick, then trimmed them with a utility knife for a good fit. Didn't plan it that way, but worked well. Thank you very much for this idea!


    4 years ago on Introduction

    Great idea! top tip for silicone release...spray soap. Spray it on anything you don't want silicone to stick to. Detail preserved. Any soap will do.


    6 years ago on Introduction

    I made these over the weekend and they turn out great, but one thing that no one seem to mention is the lingering vinegar smell. I have them sitting outside in the garage for 5 days and the smell is still pretty strong. If the smell never goes away...I'm not sure if they will be useable!?!


    6 years ago on Introduction

    I used an old pair of shoes or buy some cheap $10.00 shoes.A medical styled plastic glove is better than Vaseline. Cut off the uppers, lie in a thicker ziplock style sandwich bag and smooth out all folds and mix your Silicone and choice of hardener and use whatever to spoon it out into the interior of the shoe. Place another piece of GLAD or generic wrap on the mix. Place your foot onto the shoe. If you put you weight on it you might just clear out all mix from your heal. That would be defeating your purpose. With a small bit of weight on mix won't be helpful for your arch? There is a balance of need here. Can you get complete help with the Arch, Heel, and Ball of you feet? I didn't get anything better than Dr. Who-ever that sells insoles at Department Stores. You WILL cramp your feet into a shoe already in your closet and make them unusable. So back to the store with $ to buy shoes that fit your home made insoles. Good luck!


    8 years ago on Introduction

    You can add corn starch to your silicone instead of the glycerin. It will allow the silicone to fully cure as well. Be carefull by adding too much corn starch you can accelerate the cure time drastically.

    2 replies

    Reply 8 years ago on Introduction

    up to fifty fifty by volume. Any amount above 10% will still allow the moisture to cure the silicone. just a bit longer.


    8 years ago on Introduction

    How strange, I just made something like this last night with oogoo! I did a different method but I like your idea! Very innovative! Could also use a plastic bag (zip lock freezer bag type?) because silicone peels off them so you would just have the silicone for the insole which would be easier to wash and so smell less! (Not a judgement on your feet, just feet and orthotics in general!)

    3 replies

    Reply 8 years ago on Introduction

    i chose to use socks, for the cloth feel (most insoles have a cloth layer so your foot has a bit of air circulation).

    And now you gave me a good idea. put a piece of plastic wrap on the top so your feet will not get sticky, when you make them, then just peel the plastic off.


    Reply 8 years ago on Introduction

    Yeah I've made mine with a sock too for that reason, should survive the washing machine!
    Another thing you can do to stop it sticking to hands or feet is use vaseline (petroleum jelly) on them. Just rub it into your skin and the silicone shouldn't stick.