Allied Seawind 30 Integral Water Tank Build

[lsheaf]

Hey guys,

Here are some photos of my AS30 integral water tank build.

I must say this has been the most challenging project I’ve undertaken so far, mainly because I live on board. Removing the old tank along and grinding back all of the thicken resin holding the tank in place was quite the job! However, I have been lucky to spend a few nights elsewhere while the fiberglass layup was curing.

I have cut all of the baffles out of 3/4” plywood but am becoming more concerned about possible water intrusion.

What do you guys think about solid fiberglass baffles? 4-5 layers of Biaxial fiberglass and then trace out the plywood baffles I have fitted already.

[lsheaf]

More pictures.

I did layup some biax in case I decide to make solid fiberglass baffles. If not I can always use it for backing pads and other projects.

[atomvoyager]

3/4" ply is thicker than what's needed because it will have at least one layer of glass on each side. For these small baffles 3/8" is sufficient or 1/2" max. I just made an integral water tank using all Divinycell foam board for sides, top and baffles to save some weight and stop any chance of future rot. Your solid fiberglass baffles should work fine with the advantage over glassed plywood that they can never rot. You mention the number of layers, which I assume is a thick fiberglass such as 1708. In that case, depending how large the unsupported area is, they should be OK. You don't want them flexing and cracking so 1/4" thickness would be a good minimum. Larger panels, say over 16", would need to be thicker. In that case the cost and weight of solid epoxy/glass no longer makes sense and you should switch to foam core. Yours are not large so weight and cost of them is not much of an issue. You can also use G10 but may be cheaper to make your own.

[atomvoyager]

It may be a photo illusion, but the white color in your new fiberglass in the bilge looks like it may have insufficient resin, or what's called a dry layup. Usually the glass is more transparent when properly wetted out. Not possible to fix it easily in this situation other than adding another thinner layer of cloth on top with plenty of resin to ensure water cannot penetrate the dry fibers below. In the future, to make sure you have the glass saturated on thick fiberglass such as 1708, first apply resin to the bonding surface, and then to the back of the glass, then lay it in and apply more to the top. Don't try to do too large an area at one time or it may start to harden up before you get it all wetted out.

[lsheaf]

I did grind back most of the unsaturated fiberglass. I believe some of those spots absorbed water from the forward bilge after I left the boat. I did add another 1-2 layers of 1708 on top and I’m confident it is well sealed at this point.

In the next photos I prepare the new fiberglass baffles to be tabbed into the tank. To ensure the bottom of the new cabin sole sits flush with the top of the baffles, I made a template using plywood and small pieces 1” x 1” x 4” pieces of planed mahogany. I fit one side of a Mahogany piece flush with top edge of a given baffle, predrilled an 1/8” hole through the baffle and mahogany, and screwed together. Repeat for each baffle. Then on the bottom of a piece of plywood, I fit each baffle into place and screwed the baffle component into the plywood via the piece of mahogany.

This allows port and starboard adjustment of the latitudinal and longitudinal baffles in the tank by removing only a handful of screws when fitting the entire assembly.

I then cut two more pieces of planed Mahogany which are to support the removable arm supports for the entire assembly. The removable arms are measured to overlap the 2” existing sole flange by approximately 1/2”. The ends of the removable arms are wrapped with a thin plastic material to prevent epoxy bonding between the arm and the flange.

These are intentionally made to be removed one at a time so I could fiberglass over the tank flange with two layers of 4” wide fiberglass tape while still supporting the structure.

[lsheaf]

Photos

[lsheaf]

A bad picture of one of the removable arms while fiberglassing the flange.

[atomvoyager]

That jig solution is clever and will work but is more elaborate than what's needed to temporarily hold the baffles in place. I just make a cardboard pattern of the baffles using a string as a guide for the height with about 1/8" gap between baffle and tank top and then cut out the baffle. Once I've got it shaped to fit I secure it in place either with tape on one side and then start glassing in from the other side or if I need it held more securely I carefully drill a few 1/8" holes about 3/8" deep into the hull along the edges of the baffle and secure it with #8 x 1/2" stainless screws. Then I apply a bead of thickened epoxy along the edges and before it hardens lay the glass tape over it.

When I'm ready to place the tank top I put a bead of thickened epoxy on the top edges of the baffles and the perimeter of the hull to bond to the top as it's lowered down. Then only the top of the tank is glassed to the hull around its perimeter.

[Lloyd]

Big project. Baffle jig looks really good. Holds them good while allowing plenty of room to work around.

[lsheaf]

Looking back, I probably could have saved a lot of time by doing something more simple but I am pretty satisfied with the results. Sometimes I’m too much of a perfectionist and make things more complex than needed.

As for a water pickup fitting, will a plastic fitting sealed with silicone be suffice?

[atomvoyager]

That will work. You may have noticed in my tank videos that I use a 1/2" mushroom outlet when, as in your case, the lower end of the tank is accessible. I've been using Multicaulk but silicone can work. Otherwise I epoxy in from the top a 1/2" OD copper pickup tube that reaches the bottom.

[lsheaf]

Thanks for the response. I’ll look around and see what I can find for a mushroom fitting. Otherwise I have some 1/2” and 5/8” copper refrigerant tubing I can use.

[atomvoyager]

West Marine has a Plastic Mushroom Head Thru-Hull Connection, Barbed for $12. I get them wholesale for $5. I guess it would be much cheaper to use the copper tube you have on hand and glass a piece in horizontally near the bottom of the tank. I assumed you'll use a Whale foot pump but if using some electric pump then maybe a different OD is needed.

[lsheaf]

I should be able to get over to the marine store this week and maybe pick up a fitting. Otherwise I’ll probably stick to the copper tubing I have. At the moment I don’t have a whale foot pump but that is on my list. I only have an electric one at the moment.

Here is a new better picture of the fiberglass baffles before coating and after coating with Brewcoat.
I applied 3 coats but there a few spots that aren’t completely white. Mostly on small pointy parts of the layup.

[CapnK]

Love that you posted this, about to start on the tanks in my Ariel.

[lsheaf]

Thanks!

Here is a update picture of the new sole/tank lid fiberglassed into place. I’m thinking about just painting it with Interlux Brightside and putting some kind of “baseboard” trim piece around the edge of the new sole. What do you guys think?

[atomvoyager]

Looks good. I don't see any benefit to adding trim. If the trim is trying to hide a rough fiberglass joint I'd prefer to use fairing compound and sand it smooth. If you varnish the trim then you'll keep varnishing since it gets wear underfoot and traps dirt at the edges. But all that is just personal preference so do what suits you. I try to avoid a single part paint for the same reason that it soon gets damaged. I'd just tape off the edge and do a darker color on the sole with two-part in light brown or medium gray with coarse non-skid additive mixed in.

[lsheaf]

Thank you,

The trim pieces are just to cover the rough cut edges on the plywood. I accidentally discovered while rinsing fiberglass dust off the new sole, that water channels around the sole back into the bilge, even with a heavy bow. I think I will install scuppers aft of the sole for good drainage. I learned on my trip to Guadeloupe, there was no place for water to drain off the old sole. It was very tiring having to wake up and sponge up water in the night. Then again, that water probably shouldn’t have been getting in the boat anyway.

Anyway, I don’t really mind the fiberglass edges as much. It may be good future reference if something need to be repaired.

I ended up using a single part on the sole and will most likely pay for it. The only two part system frequently available on St. Thomas is Awlgrip. The local marine stores don’t sell enough Interlux perfection and the hardener goes bad.
I have a gallon on Snow White Awlgrip but am saving that to paint my hull and topsides.

[atomvoyager]

For future reference, you can use Interprotect 2000e epoxy primer (gray or white, which is a light gray color) as your interior locker paint or even for the cabin sole with no paint over it. Easy to apply, covers in two coats with no sanding between coats and lasts forever.

[atomvoyager]

By the way, you didn't mention if you used an epoxy primer before applying the single part paint on the sole, if it was bare wood or sealed in epoxy resin, but I found that a single part primer or paint does not adhere well to epoxy resin. Sometimes it will stick a little better if the epoxy resin has been curing a long time, as in months, but not when it is fresh. So even if you want to use single part paint you should first apply epoxy primer, let it cure several days, and sand it good before painting over. Even that is no guarantee but it gives a better chance of success. To test how well your paint has adhered and know if it will last, you can push a piece of masking tape down hard on the edge and pull it up. If the paint comes off on the tape then it's going to be wearing off during use.

[lsheaf]

I forgot you did mention interprotect 2000e at one point. If this finish doesn’t last long, it’s pretty easy to sand and re-prime with interprotect.
I know that it is available locally too.

I hopefully will be ready to fill my tank after installing the Beckson deck plate fittings today.

Do the screw holes need to be prefrilled and filled with epoxy? Or will the silicone seal help prevent water from getting in the screw holes?

[atomvoyager]

You don't absolutely have to epoxy fill the holes if you make sure you don't drill all the way through the wood to the inside of the tank. Silicone may work but Bed-it butyl will be more reliable.

[pmnfernando]

tank is looking good!!

[lsheaf]

Thanks Fernando!

Hey James,
So I sanded back as much single part paint as possible but have left the deck plates in place sealed with Sikaflex. Do you think it will be okay to tape around the deck plates and then paint the sole with the interprotect?I am slightly worried the interprotect will melt the sikaflex but either way I guess it worth a try.

Logan

[atomvoyager]

It should be no problem.

[lsheaf]

Hey guys,

After stripping back all the one part paint I coated the new sole with 2 coats of interprotect 2000e. The coating already seems much more durable and dries much faster than the one part I was using.

I see the light at the end of the tunnel!

[CapnK]

Looking great!!!

[lsheaf]

Thanks, the tank itself is fully functional I’m just waiting for the marine store to restock some white 2000e to finish painting. More pictures coming when it’s fully painted.