DIY Diesel Tank Planning Advice

[bobfnbw]

why do all that when you can just use this
Moeller Low Perm Permanent Below Deck Fuel Tank - 19 Gallon

I used this as a day tank on my Endeavour 40. just make sure its well secured. They make other models as well.

[GILow]

Originally Posted by bobfnbw

why do all that when you can just use this
Moeller Low Perm Permanent Below Deck Fuel Tank - 19 Gallon

I used this as a day tank on my Endeavour 40. just make sure its well secured. They make other models as well.

Well Mr Banghead, possibly because that tank won't fit in EITHER of the locations documented in the thread.

:^)

[bobfnbw]

Originally Posted by GILow

Well Mr Banghead, possibly because that tank won't fit in EITHER of the locations documented in the thread.

:^)

Well excuse me but I don't seem to recall any part of the thread that documented the specific dimensions. Or maybe I missed that. Either way, a ready to use tank would be a lot easier. Unless of course it won't fit, then have one made from aluminum. Cost more but worth it.

[GILow]

Originally Posted by bobfnbw

Well excuse me but I don't seem to recall any part of the thread that documented the specific dimensions. Or maybe I missed that. Either way, a ready to use tank would be a lot easier. Unless of course it won't fit, then have one made from aluminum. Cost more but worth it.

No, what you failed to do was read the perfectly clear description in post #1 or look at any of the good photos in post #10.

If you had taken the time to do so you would know that neither poster had a location where a ready to use tank would be even remotely likely to work.

In both cases the posters have, in my opinion, selected the smartest way of making the most of the space available by building in the tank. All that remained for them to do was choose the best construction method.

No need for patronising emoticons that express frustration with their thinking which was perfectly sound.

[zstine]

Originally Posted by bobfnbw

why do all that when you can just use this
Moeller Low Perm Permanent Below Deck Fuel Tank - 19 Gallon

I used this as a day tank on my Endeavour 40. just make sure its well secured. They make other models as well.

Bobfnbw, I can't fit this tank where I want to put mine. The biggest off the shelf tank that fits is only 13gal, while I'm going to have about 20 with my custom tank... plus I'm going to have it done for under $200.

[zstine]

I'm looking for a fitting to attach the supply and vent to the tank. Because this is FRP, I don't want to thread and NPT fitting into the tank. I want to use a bulkhead like fitting that has an O-ring to stop leakage with a female 1/4"NPT. BUT I've spent several hours searching and none of the brass 'bulkhead' fittings have O-rings and are not designed for in-tank applications.

Can someone help me find a supplier for a thru-tank fitting?

Thanks!
Zach

[Rhapsody-NS27]

I've tried looking but seems a lot of fittings are for drill & tap or welding in place... at least for fuel specific fittings. Otherwise, just look for bulkhead fittings and you might find something that could work.

Also wanted to note... for any gaskets, make sure you find one that's resistant to the fuel you're using. EPDM I read isn't compatible with Diesel... but vitron is.

[Rhapsody-NS27]

Not sure, but this might be what you're looking for.
Arlington TN | 1/4" Brass Bulkhead Fitting

[sv.antea]

In 1983 I have replaced the Atomic 4 in my Yankee30 with a universal M25. The precariously mounted galvanised steel gas tank had to go. Built in 22gal tank out of 1/4" plywood, f/g cloth and West epoxy, right into the V of the hull under the cockpit. First I glassed over and recoated the hull and part of a plywood bulkhead about 6" around the footprint of a coffin like lid. The interior of the lid was covered with three layers of 6oz cloth and recoated to fill any pinholes. The lid was then glassed in.
The result survived two severe groundings, two trips to Europe, handful of gales. I also believe that built in tank, by keeping the temperature of the fuel more constant (close to the surrounding water) and the insulation properties of the plywood top help keep condensation in check. My Racor rarely accumulates few ccs of water and in the 33 years since, I had no problem with algae. Just saying.

[zstine]

Originally Posted by Rhapsody-NS27

Not sure, but this might be what you're looking for.
Arlington TN | 1/4" Brass Bulkhead Fitting

YES!! thank you, thank you, thank you...

This is the exact one I found a few weeks ago, but didn't save. I was going crazy looking. Plastic-mart for a brass fitting.. go figure.

I owe you a beer!

[zstine]

Material compatibility in Diesel...
I bought 1.5" filler neck from Summit racing ($15) and also bought the gasket ($4). BUT the gasket is Neoprene.
Doesn't Neoprene break down in fuel??
Can I use Butyl tape to seal the filler neck or will that also break down in fuel?
Thanks!

[GILow]

Originally Posted by zstine

Material compatibility in Diesel...
I bought 1.5" filler neck from Summit racing ($15) and also bought the gasket ($4). BUT the gasket is Neoprene.
Doesn't Neoprene break down in fuel??
Can I use Butyl tape to seal the filler neck or will that also break down in fuel?
Thanks!

I've been following your build questions and it occurs to me to ask if you can run your pickup and filler fittings out the top of the tank? My reason for asking is that I had none of these problems with fittings as I simply epoxied the various fittings for my tank straight into the top of the tank. The fittings themselves are therefore always above the fuel, and aside from splashing, do not need to be as perfectly sealed. So far, after about four months of use, there is no apparent seepage around the fittings.

Matt

[huller]

A good epoxy coating is enough as this is a 20-gallon tank. Choose a good brand and make sure it will last long and is insoluble in organic solvents. trash:

[zstine]

My tank build is done and I will post some pics and details later, but I now have a question about installation. USCG A1 fuel line made of NBR/PVC is about $3+/ft, while I can buy SAE 30R7 premium automotive fuel line also NBR/PVC for $0.80/ft. Is there a real difference between the 2, like the difference between tinned marine wire and bare copper wire, or is this a case of the USCG stamp/cert just adding to the price without any real difference in product? After all, the automotive fuel line survives for decades in a fairly harsh place, so why is it bad on a boat?

Thanks!
Zach

[zstine]

Here’s the skinny on my tank build:
Template for the tank with cardboard then cut 3/8” exterior plywood to templates. I used stainless staples in an air gun to put the ply wood together, without the top, but you could probably get away with duct tape as this is not structural. Gaps up to 1/8 inch are not a problem, because I next used thickened epoxy to go over all seams and used 1.5” pvc to get radiused fillets. And I epoxied in GPO3 sheet (onlinemetals) inserts in places that were going to have penetrations. Then I glassed the inside with vinylester resin starting with 3” wide tape over seams, two layers, then 4 layers of 9.6oz glass and finally glassed in a baffle. I drilled a ¾” hole (spade bit is best for this) for the fuel supply fitting (items 1, 2, 3) and did a capacity and leak test of the tank with water (pic1)… nearly 25gal. double the capacity an off the shelf tank would have! For the top I layed up 4 layers of vinylester on a piece of glass and then put the plywood on top with several weights to press it into the glass. I then made holes for the fill (item 4), vent (items 5 & 6) and sending unit (item 7). The nuts for the fill were epoxyied on the inside and coated with vinylester resin (pic2). The holes for the sending unit were tapped to use the special Moeler fasteners. I then scuffed the matting surface, cleaned everything and set the top on the bottom with a bead of thickened vinylester resin (item 8) on the edge of the bottom. Weighed the top down and allowed that to cure. I then trimmed the overhang off the top and covered the whole exterior, save gasket areas, with 3 layers of epoxy reinforced fiberglass and an extra layer of 3” tape on the seams. Last was installation of the fittings and it was ready to install (pic 3). Tank cost me maybe a bit over $200 with all the wood, glass, resin and fittings.
Items:
1) 1/4" Brass Bulkhead Fitting (Includes Viton O-Ring) $9 + S&H plastic mart
2) Kingston KMBVM Series Brass Mini Ball Valve, Lever, 1/4" NPT Male x NPT Female $7 Amazon
3) Anderson Metals Brass Hose Fitting, 90 Degree Elbow, 5/16" Barb x 1/4" Male Pipe $6 Amazon
4) 1.5” straight fill with gasket from Summit Racing $20est.
5) RAINPAL BBF020 Brass Bulkhead Tank Fitting (1/2 inch Female Pipe and 3/4" Male Garden Hose Threaded) (1) $8 Amazon
6) Anderson Metals Brass Hose Fitting, Connector, 5/8" Barb x 1/2" Male Pipe $6 Amazon
7) Moeller Marine Electric Universal Fuel Tank Sending Unit (4" to 28" Deep Tanks, 32 to 240 Ohm's) $28 Amazon
8) Vinylester Resin, 1 gallon, Hydrex 100 Vinyl Ester Laminating Resin, $57 fiberglasssupply