Thinktank Revision 2.0

[donimo]

I have that GE stuff, I hated it, took forever to dry and then peeled right off in a mealy mess...

YMMV

awesome project, I have a ton of old medical equipment that I saved from the garbage, suction pumps, bunch of stuff, let me know I may have something that would cost you a ton that might be useful, for free of course

[BrainEater]

Thx !!

I appreciate the offer.

I've actually got everything I need , for the most part , it's all about fabrication and assembly now.
-------------------------

Originally Posted by donimo

I have that GE stuff, I hated it, took forever to dry and then peeled right off in a mealy mess...

I can tell from your description what happened.

One-part RTV silicones cure by absorbing moisture from the air , and releasing Acetic acid....

From a physical standpoint , what this means is , any section thicker than about 1/4 inch thick , won't cure properly , as it self-seals from the atmosphere , preventing moisture absorption.....
-

GE silicone II is actually the best generally available silicone around...
GE silicones (now called Momentive performance materials) is the undisputed world leader in silicone technology.

The RTV-157 shown in that pic and the GE silicone II are both made by Momentive.They are basically the same silicone.....The RTV-157 has been tested to a much greater level (MILSPEC/aerospace grade).

[Shadowmeph]

From a physical standpoint , what this means is , any section thicker than about 1/4 inch thick , won't cure properly , as it self-seals from the atmosphere , preventing moisture absorption.....

I didn't know that I have always thought that it just took longer to Cure. I will have to remember this

[donimo]

Originally Posted by BrainEater

Thx !!

I appreciate the offer.

I've actually got everything I need , for the most part , it's all about fabrication and assembly now.
-------------------------



I can tell from your description what happened.

One-part RTV silicones cure by absorbing moisture from the air , and releasing Acetic acid....

From a physical standpoint , what this means is , any section thicker than about 1/4 inch thick , won't cure properly , as it self-seals from the atmosphere , preventing moisture absorption.....
-

GE silicone II is actually the best generally available silicone around...
GE silicones (now called Momentive performance materials) is the undisputed world leader in silicone technology.

The RTV-157 shown in that pic and the GE silicone II are both made by Momentive.They are basically the same silicone.....The RTV-157 has been tested to a much greater level (MILSPEC/aerospace grade).

Offer stands (to anyone really) I can't throw anything away, and most of it is medical so it is quite high end, but often useless for anything else...

I put down a 1/4" bead and then finger smoothed it to about half that, it took about a week or more to dry and then peeled right off with its first cleaning, hmmph. maybe just a bad batch?

[BrainEater]

That's totally possible , but that's probably not it.I've done a lot of silicone work , and I can tell you for a fact , surface preparation is 50 % of making any silicone work , especially from an 'adhesive' standpoint....

The whole curing thing is the other 50%......The specs for proper curing are actually fairly specific......deviation from these specs will cause issues....

If you are trying to do sections thicker than 1/4" , you need to look into 2-part silicones , and these are all aerospace type materials a.k.a. really expensive....I found silicones worth 2000$ per litre......This isnt something you use for bathtubs or anything.....

----------

I'm the same way with collecting stuff.......It takes me years to decide to throw stuff out......

[BrainEater]

Update :

I actually spent a couple hours writing down a list of all the things I need to do to make this sucker run.

The list has ~20 sections with a total of about 100 individual requirements , so we're looking at about 500 things to do.....heheh...

[donimo]

I prolly just screwed it up, I do that a lot.

Let me know if you need anything that you could imagine might be also used in a hospital, I have parts that cost fron $5 to $50,000 sitting in my store room...

[BrainEater]

Yea I do that too.....hehehe

That's very generous of you !! Thank you for the offer.

The only thing I can think of at the moment would be a 'high vacuum' pump.......mine's not for 'hard' vacuum'.........

That's not for this project though , it's for another mindfart.

[donimo]

nothing at the moment that can pull that, I have tons of suction pumps, but they are the Gomco ones, pull like 30 inHg, not what you want, the lab has stuff like that I think, but they tend to keep that stuff for themselves, buggers...

I have a whirpool pump....

gas analyzers...

large capacitors from defibs...

weird motors...

600w xenon light sources...

Im just being silly, but yeah I will keep a lookout for stuff I think you could use, I just purged 3 months ago, too bad I had some crazy stuff...

[BrainEater]

Awesome !!



Man , I collect stuff like that whenever I get the opportunity ! I had the great fortune to be able to gut a portion of a DC-3 cockpit....back when I was 10.....Great stuff !!

--------

I've done some work. :

I soldered the male threads onto the drains :



-----

I let the front of the tank gap soak for 4 days in distilled water :



I think thats clean enough....you can still see the spots at the top and the spot at the bottom , but it's sooooooo much better........That'll do !

-----

Test results :



The silicones do not seem to affect either of the foams , but you can see that the black foam is altered by Isopropanol......it appears it looses 'plasticizer' .....

Not a big issue tho , that black foam (armorflex) is not generally exposed to Iso.

The good news is the grey foam.Iso doesnt appear to touch it.....So I have my backplate/gapping material.

----------

I'll be starting the final seals in the tank tomorrow.



edit : Thx for leavin post 500 for me !!