My 315G Plywood Tank Build
- Thread starter BadOleRoss
- Start date
Two things:
You don't want to go with a thick coat first. You want consistent thin coats that build up to 60-80 mil. 60 is about as thick as a dime or 1.25 mm and 80 is about the thickness of two credit cards (recommended by Scott at USI).
You do NOT want to apply silicone to Pond Coat. Apply the silicone first then when it is cured apply the Pond Coat over it. While Pond Coat does not bond well to silicone, you can bridge over it. Meaning that you can have it go from the wood to the glass or acrylic with cured silicone between the wood and glass/acrylic. It sticks really well to either side of the silicone.
Cured silicone will NOT break down Pond Coat over time. Cured silicone is inert. It is uncured silicone that WILL break down Pond Coat. Uncured silicone releases acetic acid (that vinegar smell) as it cures. The acetic acid is what eats at the Pond Coat.
Also, Pond Coat does NOT breakdown when submerged in water.
Just FYI, I'm looking into becoming a distributor for Permadri products.
You don't want to go with a thick coat first. You want consistent thin coats that build up to 60-80 mil. 60 is about as thick as a dime or 1.25 mm and 80 is about the thickness of two credit cards (recommended by Scott at USI).
You do NOT want to apply silicone to Pond Coat. Apply the silicone first then when it is cured apply the Pond Coat over it. While Pond Coat does not bond well to silicone, you can bridge over it. Meaning that you can have it go from the wood to the glass or acrylic with cured silicone between the wood and glass/acrylic. It sticks really well to either side of the silicone.
Cured silicone will NOT break down Pond Coat over time. Cured silicone is inert. It is uncured silicone that WILL break down Pond Coat. Uncured silicone releases acetic acid (that vinegar smell) as it cures. The acetic acid is what eats at the Pond Coat.
Also, Pond Coat does NOT breakdown when submerged in water.
Just FYI, I'm looking into becoming a distributor for Permadri products.
Thank you Pete, OK, when you say "cured silicone" I assume you speaking of the normal 7 to 10 days that we allow for it to cure when sealing our glass? My glass will be sealed into a frame much like you are doing on your 4300. The only piece of the puzzle I am missing is the "bridge" over the silicone that will be on the outside edge of the glass. This will be a very small gap 1/4" or less so I may let the silicone cure up real good and then top coat that with several layer of PC. I will be moving the tank into the house this Wednesday getting it ready for glass. Glass should be here late this week or early next week.
You're not understanding what I mean by bridge, so here's a drawing.
blue is the glass
red is the cured silicone
black is the pond coat
See how it goes from the plywood bottom
then bridges over the cured silicone
to the glass?
Think of the cured silicone as a river. The glass is one bank of the river. The plywood is the other bank of the river. The PC is the bridge over the cured silicone river from one bank (the glass) to the other bank (the plywood).
blue is the glass
red is the cured silicone
black is the pond coat
See how it goes from the plywood bottom
then bridges over the cured silicone
to the glass?
Think of the cured silicone as a river. The glass is one bank of the river. The plywood is the other bank of the river. The PC is the bridge over the cured silicone river from one bank (the glass) to the other bank (the plywood).
Now if you look at my build for the 4300 and for the 90 gallon expansion, you'll see that the Dow 795/Silicone never come in contact with the Pond Coat.
We just attached the glass for two of the 90 gallon expansion tanks; the 170s. We put silicone between the front frame and the glass. There's no silicone inside the tank. The PC will go from the plywood on to the glass. The silicone cushions the glass. The PC makes it water tight.
We just attached the glass for two of the 90 gallon expansion tanks; the 170s. We put silicone between the front frame and the glass. There's no silicone inside the tank. The PC will go from the plywood on to the glass. The silicone cushions the glass. The PC makes it water tight.
Would perhaps that mesh tape for the corner seems placed over the silicone help with the bridge or would it just be a waste of tape?
Ok Pete, I see what you are saying. I was trying to go over "bridge" the silcone without touching it. Guess I just need to cover it. I do have some of the mesh seam tape left that I may place over the joint just for a extra little something.
