Bar Rust 233 curing question

[mikebikeboy]

Hello everyone, I've made a integral water tank using divinycell. I'm now at the stage of painting it with Bar Rust. The final coat I rolled on kinda thick and several days later I can still indent it with my fingernail. I remember previous coats dried almost rock hard. Did I do something wrong or does it just take longer to cure if the layer is thick.

If I did something wrong I suppose I'll need to sand off that top layer and do it again.

Mixing this stuff using mixing cups is kind of difficult because it's so thick. Maybe I got the ratio off.

[atomvoyager]

Welcome to the group. I have a similar job coming up on a CD27 and would be curious to hear more about your tank like the dimensions and location and estimated capacity. If the mixing ratio was correct then just give it more time and turn on a heater if temps are low. If the mix ratio was off it will never fully cure. Sanding it off may not be feasible so as long as it is mostly cured then you might just add another coat or two on top to seal it in.

[mikebikeboy]

Thanks for the tips about Bar Rust curing. It has been lower temps here so I'll put a space heater near it and see if that speeds up the process.

The original water tank in my CD27 was a 24-gal plastic tank which was cradled by the liner. Between the liner and the hull was quite a lot of empty space so by making the integral tank I'm guessing I'll gain at least 10 gallons. Forward of the tank was another large unused space which is now a sizeable locker. I brought the tank aft to part of the liner that makes up the port / starboard v-berth lockers and used the liner to support it. May not be the best approach but I didn't want to cut out the liner and have to redo all the furniture.

I'm using the 10-inch beckson port, and it's at the cushion level so I hope this doesn't end up being a weak point or leak. But I have a backup plan. If the 10-inch port leaks or cracks I can cut a circular piece of stainless and bolt that down into the stainless threaded inserts I epoxied into the lid. And then have a smaller beckson port in the center of that, just large enough for a hose for filling the tank.

I also glassed in the PVC pipe cut lengthwise in half, into the bottom of the hull, for the anchor locker to drain and I ran the existing lightning protection wire through there as well.

By the way all of this work was done following the page on your website so very much appreciated you sharing that knowledge!!!

[Edit: CapnK] Hey Mike, I checked out your linked image page, and found that if you go to bottom of the page there where it says "Thumbnail image (linked)", then 'Copy' the "BBCode" link, and paste that text into your post one after another, you'll wind up with the following result.
Note that this is *only* intended to be a helpful tip for you, for reference if you want to do it that way. No worries either way. Welcome aboard here, and Fair winds! - Kurt

[Edit: mikebikeboy] Thanks Kurt, great tip. That's exactly what I was attempting to do, display the thumbnails like that and save the forum some hosting space.

[atomvoyager]

Thanks for the details. You may not notice if the 8" (10" OD) hatch leaks until sailing heeled with water pressure constantly sloshing against it. I had a Beckson 8" drip slightly on a deck installation and was able to stop it with silicone paste lubricant on the o-ring. Because of that experience for now I stick to the 6" (8"OD) for tanks. If the stainless adaptor plate doesn't work out you could use 1/4" G10 fiberglass board.
Your photos did not come through for some reason. In future you could try posting one at a time on separate postings.

[mikebikeboy]

Great idea to use 1/4 G10 board ! That will be much easier to shape and work with and I'll bet plenty strong. I may just go ahead and get that going because ever since I got the 10' Beckson port and noticed it flexes a bit I assume it's probably going to leak.

I edited my post above so you should be able to click on the image links now.

[atomvoyager]

The images are visible now with a click. I'm assuming you have the tank top not glassed down yet so you can bring the top inside the house next to a heater for 24 hours and then run a space heater on the boat when it's safe and then compare the hardness of each. If it still doesn't fully cure, do a small test mix and see if that one cures faster. If so, then your mix ratio was off.
If not too much trouble I'd like to get the inside tank measurements - fore and aft length, height of center aft, height of center forward, width of top aft, width or top forward.
The reasons I've gone to the trouble of putting a shallow locker above my tanks are:
1. If the inspection port ever leaks, the water won't soak into the cushion and flow all over the bunk. Filling spills are also better contained and easier to wipe away.
2. Keeps the weight lower, although that means for the same volume tank it needs to be longer fore and aft.
3. The locker above helps deaden sloshing noise when the tank is over half full. That may not be an issue since the cushion is a sound deadener anyway.
4. On my latest divinycell tank I made the upper site tube fitting attach to the top of the tank with a 90 degree thru-hull and another 90 fitting pointing down so that it reads when closer to full. That's not too important though.
5. Reduces the uneven lump where it might be felt through the cushion because of a raised inspection port. This may not be an issue at all but if it is you could trim away some of the cushion bottom foam above the inspection port.
All that probably doesn't matter much in the end and eliminating the shallow locker on top saves a lot of labor, material, weight and the parts for the hatch. And the shallow locker has limited useful storage. And if the tank is larger than needed most of the time you simply don't need to fill it to the top.

[mikebikeboy]

I'll grab the dimensions next time I'm up at the boat, in a day or two.

Yes, I still have not installed the lid. Currently I've got one coat of Bar Rust on the tank and 3 coats on the lid. The lid does seem to be hardening slowly after I put it next to a space heater for 8 hours. I'll continue that and see if it cures even harder. If it doesn't, it won't be an issue to sand the lid down and recoat.

I decided not to make a site tube and instead I'll make a dip stick with markings on it.

Regarding shallow locker above tank. I suppose someday I could add that if any of the issues you mentioned plague me, but I'll cross that bridge later. I do hope the sloshing noise isn't too loud while at anchor.

[mikebikeboy]

Here are the dimensions of the tank in the CD27, in inches:

fore and aft length -26.5
height of center aft - 23
height of center forward - 14
width of top aft - 56
width or top forward - 32

[atomvoyager]

Thanks for that. My guess is that the capacity will be at least 40 gals. Hope you come back later after filling it and tell us the actual capacity. Looks like a good size for the boat. Normally it won't be an issue but you don't have to fill it all the way when concerned about trim or carrying all that weight underway.

[mikebikeboy]

I will definitely return with the information about how much water it holds, some final pics, etc.

[mikebikeboy]

I've made the new lid with the 1/4' g10, and reinforced it with some 1/2' I had laying around, so this lid will never flex when crawling over the v-berth on your knees. I've chosen to use a standard stainless water deckfill fitting, that'll go into the hole in the middle. I think this will solve my fears of the 8' (10' outer diameter) beckson port leaking. This thing is bomb proof.

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Screen Shot 2022-04-23 at 8.34.59 PM.png (329.63 KiB) Viewed 10215 times

[mikebikeboy]

Question for Atomvoyager: you mentioned in your article that you washed the Bar Rust with detergent after it was cured and ready for finalizing. What detergent did you use? Can I use a normal household clothes washing detergent?

Also, do you have a product link for the inline filter you use between the tank and the faucet spigot? Thank you.

[mikebikeboy]

Here's what my tank looks like right now, before bedding the lid.

[atomvoyager]

I use any detergent for dishes or laundry. The filter I used to use was called Under Sink Household Water Filter by Glacier Bay that I bought at Home Depot and once on Amazon. That one had to be tightened very hard not to leak and when it wasn't available recently I just went in to Home Depot and bought the same type of a different brand and found it tightens easier without leaking. I like the clear plastic housing ones so I can see when the filter is discolored but you could use the opaque ones and just replace the cartridge once or twice a year. Whichever brand you buy, toss out the standard paper filter if that's what it comes with and buy the charcoal replacement filters. You also need to buy the plastic hose barb fittings to connect the 3/4" ports on the filter to your 1/2" hose. They had those at Home Depot also but I check the threads to confirm they fit.

[mikebikeboy]

Many thanks for the information.

[vanguard64]

I did exactly the same procedure on my A30 tank 2 years ago and the BarRust coating is holding on well. I also installed an undersink filter but found that the higher filtration cartridges interfere with my galley foot pump. The pump has a hard time suctioning water through the filter on the upswing.
Marcelo
A30 #441

[atomvoyager]

I haven't noticed a problem with suction on my pump. Do you have the filter mounted on the outlet side of the pump and do you have the large Whale Gusher pump or the small Whale Baby pump? And do you have a similar charcoal filter element or something with more restrictive flow perhaps? You can see my setup at the 8:00 minute mark in the following video:
https://www.youtube.com/watch?v=Qq6mk2LjOzY

[mikebikeboy]

I was planning to replace my stock faucet which has a built in pumping mechanism with the Whale GP0418 Flipper Pump Mk 4 Hand-Operated Galley Water Pump

I have not purchased it yet. I wonder if it has enough suction go pull the water through the filter. Any experience with that unit?

[atomvoyager]

Maybe someone with that experience can comment but I wouldn't know about that. Unless you have used hand pumps in a liveaboard situation and like them I would suggest not to get one. I know the installation is sometimes easier but hand pumps are frustratingly awkward. Try washing your face or hands using soap with a hand pump for example and you'll see what I mean. I've replaced hand pumps with foot pumps on dozens of boats and it's always a welcome improvement.

[CapnK]

Great timing as I've just begin building my integral settee tanks. The G10 lid seems like a solid idea.

For a 'sight glass', have you ever tried just sawing a narrow slit in the side of the tank, backfilling it with plain clear epoxy prior to glassing, and leaving that slit exposed to view on the/an exterior face? Kind of like the transparent line on the seam of a motor oil container...

If it hasn't been tried, can anyone think of a reason it won't or wouldn't work?

[atomvoyager]

Interesting idea. I don't think I'd try it because it would need to run close to full height to be useful and that long epoxy-filled slot would be brittle and an early point of cracking under loads from a partially full tank and possible minor hull flexing at sea in heavy weather. If say one layer of glass cloth over it on the inside and outside was transparent enough then it might be OK. Or you could install a conventional tank gauge. But that also seems overly complicated and since my sight tube hose works well I don't have much incentive to improve it. But I'd be interested to hear if a glass cloth covered epoxy-filled site slot is clear enough to see through and then I might try it. The inside of the tank is going to be very dark and the outside where you view the site slot will be lighter with or without using a flashlight and I'm not sure now that affects the visibility.

[CapnK]

I'll be laying up some epoxy soon and will give it a test. Thx, James!

[mikebikeboy]

Hello, last week I finally put some water in the tank and closed the ports. Today I went to the boat and opened the tank fill to put some more water in there and gave it a sniff---smelled pretty strong in there, of Bar Rust. Put my arm in and felt around, everything feels hard, fully cured. I had also washed the inside with Dawn soap prior to putting water in it. Is this normal for the tank to still have a smell of Bar Rust after it's cured? Will this odor dissipate over time? Seemed kinda strong, which doesn't seem good since that will be my primary tank for my drinking water.

[atomvoyager]

Assuming the mix was correct, the odor will go away over time. With the charcoal filter in place you won't notice any odor or taste to the water now. If drying conditions weren't good and you put the top of the tank on without letting the coatings air dry for a week or so first then this is normal. Another thing you could do now is leave the inspection port open and run a fan over it several hours each day. Or just ignore it and eventually the odor will disappear.

[mikebikeboy]

Thanks for the info. I'm pretty sure I mixed everything correctly although I may have put coats a little on the thicker side. Not sure if that matters though. I'll get that charcoal filter and see if that eliminates the weird taste. I'm using the 5 micron filter (not charcoal) at the moment.

Also will be posting the tank's capacity at some point, haven't forgotten about that.

[mikebikeboy]

I added the charcoal filter and the water coming out tastes great now. No hint of anything other than water. Thanks.

[mikebikeboy]

Thanks for that. My guess is that the capacity will be at least 40 gals. Hope you come back later after filling it and tell us the actual capacity. Looks like a good size for the boat. Normally it won't be an issue but you don't have to fill it all the way when concerned about trim or carrying all that weight underway.

Sorry it's taken me over a year to report back on this, but I finally got around to making my dipstick and measuring the capacity of the tank. Turns out it holds 50 gallons when full to the brim which is double the stock tank's capacity, utilizing all the wasted empty space around and gaining a new locker as well. Great project and thanks for the guidance along the way.

[atomvoyager]

Thanks for the update. Since 50 gals of water is so heavy up forward on that size boat you probably don't want to fill it to the top except in a situation where you can't easily refill for a long time and need the reserve or when living aboard at anchor long term and not sailing much. Meanwhile, it's a great collision bulkhead.