DIY Diesel Tank Planning Advice

[Rhapsody-NS27]

Originally Posted by 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

Missed this post on how the build went. Hope it works out for you.

I just posted this video of my work. I didn't use any wood on it, just straight glass and vinylester. Still some work left to do but it's getting closer to finishing.

https://youtu.be/SmnaVVk5_4o