What's new
  • Please do not post any links until you have 3 posts as they will automatically be rejected to prevent SPAM. Many words are also blocked due to being used in SPAM Messages. Thanks!

Thinktank Revision 2.0

Status
Not open for further replies.

donimo

Well-known member
Joined
Oct 17, 2007
Messages
846
Location
Vancouver Island
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 :thumb:
 

BrainEater

Well-known member
Joined
Mar 19, 2007
Messages
2,867
Location
Calgary
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 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).

:thumb:
 

Shadowmeph

Well-known member
Joined
Oct 3, 2007
Messages
6,443
Location
Aldergrove British Columbia
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

Well-known member
Joined
Oct 17, 2007
Messages
846
Location
Vancouver Island
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).

:thumb:

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

Well-known member
Joined
Mar 19, 2007
Messages
2,867
Location
Calgary
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......

:thumb:
 

BrainEater

Well-known member
Joined
Mar 19, 2007
Messages
2,867
Location
Calgary
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...

:thumb:
 

donimo

Well-known member
Joined
Oct 17, 2007
Messages
846
Location
Vancouver Island
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

Well-known member
Joined
Mar 19, 2007
Messages
2,867
Location
Calgary
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.

:thumb:
 

donimo

Well-known member
Joined
Oct 17, 2007
Messages
846
Location
Vancouver Island
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

Well-known member
Joined
Mar 19, 2007
Messages
2,867
Location
Calgary
Awesome !!

:haha:

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 :

tt2_183.jpg


-----

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

tt2_184.jpg


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 :

tt2_185.jpg


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.

:thumb:

edit : Thx for leavin post 500 for me !! :biggrin:
 
Last edited:
Status
Not open for further replies.

Latest posts

Top