Well the log is 33'' long & that is the size of my tank so I hope to actually fix it right across the length but at about mid water.
Next step however will be to drill multiple holes right though the log because I would like to see the plant root exit the bottom, I also need to cut the ends at the right angle to enable a nice neat fit in the tank.
Once the holes are drilled i will completely coat the wood with several coats of epoxy.....
So I cut out the plant pockets & cut the ends to fit my tank, i will line the pockets with the green mesh to hold the soil but, allow the roots out!
I have also coated the log with two coats of epoxy, The log is now soaking in my outside rain water barrel...
I am afraid I cant give you any more until I have soaked my log for a few weeks!
I hope the epoxy will keep the log intact especially the bark but, I think it would need several more coats to guarantee a complete seal. The bark makes it very difficult to fill every nook & cranny however the log does have a very good coating.
Polyurethane should of given you a good seal too - Bondaseal G 4 is a good product.
I wrote a bit here viewtopic.php?f=21&t=13510 about making backgrounds.
I buy my epoxy wholesale in 4.5lt cans 10 at a time but, it is still expensive
I will now give some thought to how to fix the log in place, I have a few options like making up two perspex strips about 75mm wide that I can fix into the log ends & clamp to the top of the tank. This would enable me to easily remove the log for "maintenance"!!
I doubt if the log will sink even after soaking as any water ingress will be very slow?
However I want to see what happens after a few week in the water butt....
I was looking at the g4 but it would have cost about Â£40 to do and it's only a 30 inch tank
I already had the yacht varnish, so it seemed sensible to use what I had....big mistake! It took over 2 weeks to cure and as soon as it went in the water it started to melt . I was not amused having spent 3 weeks carving and covering the poly, then grouting. I make all my own backgrounds for my viv's, but I'm still struggling to find a fail safe sealant for aquariums.
Have you thought about using some powerful magnets to secure the wood? Drill a hole and fix one magnet either end of the log, with a good covering of aquaruim sealant to stop it rusting, then the other magnets would simply sit outside of the tank, securing the log in place?
~Did you look at my link - black spray foam can give good instant results without any sealer.
G4 "clear" has a yellow tinge like virtually any polyurethane varnish but it is available in black or green, you can mix the two colours to get various shades.
G4 is not that expensive about Â£15 per litre, that should be easily enough for a 30'' backdrop.
Epoxy, is not so easy to work with but will give a completely clear finish or any colour you like with added pigment however it is quite expensive at about Â£25 per litre & it wont stretch out like G4 either!
I did indeed see your link, sorry I should have said that in my previous post. I loved the cave set-up you did for your friend.
I need to build mine out of poly. It's not just the back 'wall' I will be making, but also a land area dropping down into the water so the fbt's can safely get in and out (they are not good swimmers) It will also be getting covered in a layer of coir before the final waterproof layer goes on and I wil probably be including bits of bog wood, rocks and the like as well.
The main problem I'm having is achieving a natural look. Most waterproof finishes tend to be high gloss :? (not sure if G4 is or not?) Â£15 a litre? The links I was looking at for G4 pond sealant was coming in at a tenner for 250ml.....
Yes G4 has a very high gloss but, you can apply sand to the top coat to get a amphibian friendly mat non slip finish.
You should be able to get clear for about Â£12 & coloured at about Â£15
I find that adding a few different textures & shade of sand gives a great finish - play sand, sharp sand black sand is a good combination. http://www.cfsnet.co.uk/acatalog/G4_Pon ... ured2.html