HELP - My beautiful canopy........

[Ocicat]

I started a thread on DIY asking for advice; it has the details:

http://www.reefcentral.com/forums/showthread.php?s=&threadid=906921

But in short, my custom walnut canopy is warping.

 

[geoxman]

Did he use latex or oil stain and PU? I have used marine PU in the past and it has never warped. It is warping from moisture getting into the wood. JMHO and good luck!

 

[geoxman]

After looking at the pic, there appears to be no PU on the inside of the canopy. Is this correct? If so then that could be your problem.

 

[Ocicat]

What is PU?

He used:

1) Kilz Latex int/ext water-based sealer/primer
2) Behr Premium Plus exterior paint
3) Helmsman Spar Urethane, indoor/outdoor

 

[sirreal63]

It looks to me like there is a severe lack of ventilation which will cause the wood to absorb moisture.

 

[Ocicat]

There is a 1.5" gap that runs the length of the back of the canopy, for ventilation and for cords - That isn't enough?? And that could cause it to warp within a couple of days?

 

[sirreal63]

Air must circulate to remove the moisture, if it doesn't the moisture has no place to go and the wood will absorb the moisture.

 

[Ocicat]

So what is the best way to provide ventilation - would two holes in the roof of the canopy w/those computer fans suffice?

 

[sirreal63]

It would help but the wood may not go back to it's original form now.

 

[Ocicat]

OK, but if he repairs the canopy (replacing damaged boards as necessary), then you think fans would prevent this from happening again?

Maybe 4 - one in each corner. Although, I am a little concerned about noise.

Thank you, Jack.

 

[sirreal63]

I know if you do not have good ventilation the wood will abosrb the moisture...it has no where else to go. Ventilate it.

 

[latazyo]

ocicat, for fans some people do 1 on each end, one blowing in, and one blowing out

I do them both blowing out, because it'll always find a way to get air into the canopy, I think its more important to get it out (as you may have learned)

and I can't speak for geoman, but I think PU means PolyUrethane

 

[geoxman]

polyurethane=PU

 

[chadfarmer]

if you do fans (either both in or both out) having one blow in and 1 blow out does the same as using one fan

 

[bkwudzjeep]

I put my fans blowing in, and made vents in the top of the canopy.

IME, fans blowing out don't last as long because of the salty air being pulled towards them. They corrode quicker.

Be prepared for higher water evaporation levels, but the tank water should cool as well. This will also provide the circulation the others have mentioned.

 

[scbadiver]

If you haven't already, I'd get off the top of the tank for sure. This same thing happened to my buddy Larry's hood. It was made from solid 3/4 inch oak boards and warped beyond use in just days. It had to be remade using plywood. Solid boards just have toooo much movement to be used successfully. I hate to say it but it will prbably not straighten out enough to be really usable if it has warped too badly already. I have an 8' long hood but the only thing not panelized (if thats a word!), is the top, but it is plywood and the entire inside of the hood is sealed with white acrylic so a very limited amount of tank moisture can get to the wood. Good luck with it and sorry to hear of your misfortune. It really sucks when you get something so nice and this happens. The stand looks great though! Hang in there.

 

[Hobbes8017]

FadeTheMaid's hood

FadeTheMaid's hood

When we made FadeTheMaid's hood last week, we put 4 - 4" fans blowing up and out of the top. There is going to be 5 doors on the canopy because it is 8' x 3', so the air will be pulled in through the openings around the doors. The canopy is also made from 3/4' plywood which should help prevent any warping.

Here is a picture of the fans installed in the top of the canopy.

 

[Ocicat]

scbadiver, we removed the canopy from the tank last night, but I am really afraid that it is probably too late. For strength, the stand is constructed of 3/4" plywood and wrapped in walnut... I guess we should have done the same with the canopy but for different reasons!

On the DIY forum I've been told that we shouldn't have used a latex paint with the spar varnish, because latex is water-based and the spar varnish is oil-based, so they won't bond.

Hobbes, where did you get the grills that are over the fans, and what are they made of? Can you get the fans themselves at a computer store, or did you order them?

 

[Fade]

Kelly I got the fans at radio shack for 25$ each and my buddy picked the grill covers up at a computor store I dont know where.

 

[Ocicat]

The carpenter was over last night, and he says he can and will fix it. He is going to let it dry in his shop for 4-5 days (with lots of heat and a dehumidifier) and try to use clamps to pull the wood back straight, but he isn't too hopeful that will be possible. Worst-case, he thinks he'll just have to replace the front panel and the top 2 boards that form the top part of the door.

Also he is going to put in braces, and we're going to install 4 computer fans along the length of the center roof (they will alternate with the 3 MH lights).

So now the big question is precisely what products we should use this time around to be 100% this doesn't happen again. It started warping within 2 days, so we don't think it could be only a ventilation issue, although we are addressing that also. Is an oil-based primer + Helmsman spar all we need? I am considering an epoxy paint, which I was told may be overkill, but I have no problem with overkill.