Mildewed Wood

haakebecks · Posted: Mon Jul 29, 2013 2:45 pm Post subject: Mildewed Wood

So, I've been digging into the Venture 26 going after a persistent mildew smell and found that the issue must have been a holding tank leak at some point. The factory base was all uncoated plywood and the fitting on the holding tank was barely hanging on. After pumping and flushing the tank as best we could, I pulled the hoses, plugged them and pulled the tank and existing tank base out of the boat. The tank base was black with thick mildew. I'm going to replace this with fresh material (very happy these are simple, rather easily accessible boats). What would you guys use? I don't want to drill back into the hull so brackets for King Star Board are out and everything I've read indicates that it is very hard to get any kind of decent bond between Star Board and gelcoat.

Should I simply go with plywood and paint it in some kind of tough epoxy/poly based paint?

Any suggestions are welcome!

thataway · Posted: Mon Jul 29, 2013 2:50 pm Post subject:

If you use plywood, saturate it with epoxy first--and use Marine ply which will have no voids. Another option is to use PVC lumber--not sure what is amiable locally . I have have some 1 x 4 pieces--and several "slats" of this see like it would support the holding tank base nicely--it can be glued or 5200/4200 to any substructure. It is also pretty impervious to any spills etc.

Sunbeam · Posted: Mon Jul 29, 2013 3:05 pm Post subject:

I'm not sure exactly what your setup looks like, but a couple of generic type notes that may help.

1) Mildew. Of course you don't want leaks/moisture to begin with, and dry plus air circulation keeps it at bay. However, spending some time in the tropics where it's unavoidable gave me some data on how it does on wood type surfaces. I found that wherever the wood was finished with glossy varnish, no or few problems. But duller surfaces (flat varnish, grain texture, etc.) just picked up mildew so much faster. So, shiny = good.

2) Support. In my 22, the water tank sat directly on the sole (well, no, actually it didn't, as it was too wide and they simply put it in anyway where it rested on one edge on the sole and one edge on the hull side, but it was theoretically sitting directly on the sole. Anyway, plastic tanks are supposed to be completely supported underneath. In my case adding a 1/2" sheet of Starboard (set on sole) raised the tank enough to give it complete support.

3) Attachment. My tank was originally held in by a shelf above it being attached to the locker sides with angle brackets. That didn't stop it moving side to side (fore and aft) though. For reinstallation, I affixed some Weld Mount footman loops to the sole and will secure the tank with straps. Weld Mount glue is a methacrylate and will bond well on their footman loops and on fiberglass/gelcoat.

4) As it turned out, during my project, my tank sprung a leak in an area where I was not fond of the design anyway (supply outlet at bottom of tank), so I'm putting in a new tank. I may not need the Starboard "under liner" but I will still be using the Weld Mount footman loops and straps to secure it.

Not sure if any of this will apply to your situation, but if it does...

Sunbeam

journey on · Posted: Mon Jul 29, 2013 3:24 pm Post subject:

Just curious. Where is the holding tank on the 26? On the 25's, I thought that by 2007 they went to the marine head with an integral tank.

So where did they find enough room to put a 15 gal tank that you can remove? The one in Journey On is in the space under the motor well, and the only way to get it out is to cut it into pieces. I think.

Boris

haakebecks · Posted: Mon Jul 29, 2013 4:48 pm Post subject:

haakebecks · Posted: Mon Jul 29, 2013 4:51 pm Post subject:

haakebecks · Posted: Mon Jul 29, 2013 4:52 pm Post subject:

ssobol · Posted: Mon Jul 29, 2013 5:11 pm Post subject:

haakebecks · Posted: Mon Jul 29, 2013 5:22 pm Post subject:

Well that is a bummer to hear. Basically my thought was to use it for the ribs and the base since it was just going to have a static load. However, if it is really that fragile, it probably won't be a good fit. Sure would be nice if it was easy to glue Star Board, lol!

Sunbeam · Posted: Mon Jul 29, 2013 5:53 pm Post subject:

thataway · Posted: Mon Jul 29, 2013 6:19 pm Post subject:

The PVC lumber I have was from Lowes. It seems to be fairly firm--and would hold screws well for a holding tank--but thru bolting would be better. As I understand this is just a platform--not going to take any load other than the tank. It should be fine for that. I agree that I would not hang 200 lbs from the PVC, but as a base it should be fine.

haakebecks · Posted: Mon Jul 29, 2013 6:56 pm Post subject:

haakebecks · Posted: Wed Jul 31, 2013 1:13 pm Post subject:

Well I went to Home Depot and bought a board of 3/4 and of 1 inch. I used the 1 inch for the runners and the 3/4 inch for the lateral supports. The material cuts just like wood and sanded down very well as I was test fitting.

It was certainly strong and provided more than adequate break strength for this application. I am 6'2" and weigh just a smidge under 200 pounds and I was able to stand on the platform and bounce up and down without any flexing or real concern at all. It does pick up dirt pretty easy and I've read that the cut edges are porous, so it is getting painted

I countersunk the holes, but did not glue with PVC glue as I wanted the ability to tear things apart if need be and frankly it was stout enough that it didn't need it.

I'm going to build a similar platform in the space were the existing shelves were in the cabinet next to the tank and put something like these in.

http://www.c-brats.com/modules.php?set_albumName=WorkRelease&id=IMG_0601&op=modload&name=gallery&file=index&include=view_photo.php

AstoriaDave · Posted: Wed Jul 31, 2013 1:46 pm Post subject:

I used thin slices of Trex, basically same as what you got from Lowes, glued with 4200 under my aluminum fuel tanks at chafe points in an IB installation. Stuff lasts forever, shows no mold, etc. Machines well enough I also used it as a rub rail over a coaming, again installed using 4200. On the coaming, withstands all kinds of abuse, and is slippery enough stuff does not get hung up if you slide a tote or a box over it while loading.

Too slippery when wet for any place you plan to stand, however.

thataway · Posted: Wed Jul 31, 2013 7:57 pm Post subject:

Dave, I have Trex decking on the steps to my Jacuzzi and a dock at my other house-and it does mold here in the hot and humid South. There may be some improvement in the last few years.

It sounds like "haakebecks" has PVC lumber similar to what I have--it is smooth and white. I would use epoxy to seal the ends, but if paint fills and adheres well that would work.