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Espresso machine grouphead gasket
Dan
My Isomac Millenium's grouphead gasket was good for almost two years using the gasket it came with from the factory. My machine is always on. Since then the replacement gaskets have only been lasting 6-8 months.

Tired of this nonsense, but not wanting to deal with trying to order gaskets from Italy and hoping they are as good as the original, I decided to make my own.

I cast silicone rubber gaskets using a medical grade of room temperature vulcanizing silicone rubber (RTV). This particular rubber was a little soft for this application, but it seals fine. I made the mold from acrylic plastic using my metal lathe.

After 6 months it is still as soft as when I put it in. And, it seals just fine. An additional bonus is that it is easy to remove using only a teaspoon as a lever. This lets me drop the screen for cleaning any time I want and I don't have to worry about cracking a aged gasket like I used to.

I'm going to wait until one year rolls around before calling this project a success. I thought I'd mention it now to let you know it is good so far.
 
seedlings
Dan, for some reason the pictures of your gasket casting progress (say that 5 times fast) aren't coming through. Maybe Ginny is up to no good...errr... working on the website!

s:8

Seriously, though, do you have any pics?
CHAD
Roaster: CoffeeAir II 2# DIY air roaster
Grinder: Vintage Grindmaster 500
Brewers: Vintage Cory DCU DCL, Aeropress, Press, Osaka Titanium pourover
 
Dan
Chad, Well, there's not much to see! The mold is clear acrylic, and the gasket is clear RTV. Let me draw you a picture. The gasket is round, shaped sorta like a grouphead gasket, with similar dimensions. ;)
 
seedlings
Ok, ok, ok, got your point. If you were to go into full production, what would you sell them for (the finished gaskets)? And could you match other models?

CHAD
Edited by seedlings on 07/14/2008 8:03 AM
Roaster: CoffeeAir II 2# DIY air roaster
Grinder: Vintage Grindmaster 500
Brewers: Vintage Cory DCU DCL, Aeropress, Press, Osaka Titanium pourover
 
Dan
LOL! If I were to make these, there are a number of things that influence the cost that I don't yet know. Cost of NSF RTV, labor, mold amortization, insurance, and finally longevity. After all, if it last 6 times longer than rubber... The price is the last thing I'd set, not the first. So, let's just say they would be $100 each, less as I learn more. :)
 
seedlings
"Mold amortization"? Since that's probably not finance termonology, what is it? Do you take a swab to the lab every week? I've seen the DIY petry dishes at Lowe's that one can send in to have airborne mold spores checked.

My lovely wife has the business mind, not me.
CHAD
Roaster: CoffeeAir II 2# DIY air roaster
Grinder: Vintage Grindmaster 500
Brewers: Vintage Cory DCU DCL, Aeropress, Press, Osaka Titanium pourover
 
Dan
Well, it is finance. Most plastic parts are made in molds. The cost of which should be spread out over the expected production run or life of the mold. In short runs this can be significant part of the cost.
 
David
I hope you'll do Cory vacpot gaskets next!! s:5
 
seedlings
Oh, THAT type of "mold". Gotcha Dan. I'm slow to the party.


CHAD
Roaster: CoffeeAir II 2# DIY air roaster
Grinder: Vintage Grindmaster 500
Brewers: Vintage Cory DCU DCL, Aeropress, Press, Osaka Titanium pourover
 
Dan
It has been one full year and my homemade silicone rubber gasket is still working. The gasket is slightly harder than when made, but it is still plenty soft to seal and I expect another year of life from it. The rubber is a little cloudier than when new, and there is some brown discoloration at the gap where the PF meets up and coffee grounds can rise to touch it. I don't know if it is just coffee stains or the rubber is beginning to decompose. It could be both, the rubber is harder in that region. Besides its longevity, it is also nice that I can remove this gasket to clean the screen and know that I can put it right back in without worrying about leaks. Typically, you'd have to replace the rubber gasket everytime you remove it.
 
bvwelch

Quote

Dan wrote:
I made the mold from acrylic plastic using my metal lathe.


Finally, an excuse to buy a metal lathe! -- Just look at all the money I am saving on grouphead gaskets! :-)

-bill
 
Dan
It has been two years, two months and my silicone rubber portafilter gasket is still sealing. Not a drip so far. :)
 
Dan
It has been three years and I'm still using the same homemade RTV silicone rubber groupheat gasket. This machine has been on 24/7 the whole time. :)

 
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