Re: Test Tank
Yes. You CAN successfully use either a steel or plastic 55G barrel to use as a test tank. Oddly, I found it best to think backwards!
I might have preferred a steel barrel but, cheapskate that I am, I settled on being GIVEN a heavy plastic/PVC barrel.
1. Gotta be able to drain it, right? I drilled a 1" hole about 1" up from the bottom of the barrel. A standard boat drain plug fits just right.
2. Mark a point straight up from the drain plug. A Magic Marker worked for me to create about a 2" vertical line from the very top and extending down. <-- That's gonna be the center of your splash guard.
3. From that vertical line, and using a tape measure, I measured and marked points about 8" out to each side right at the top, again using about 2" vertical lines.
4. Then I went and got all artistic with some lines of compound curves. See pic #1
5. Then I decided that I just wasn't likely to ever be dealing with long shaft (20") outboards, and besides... who needs/wants to lift one of these awkward beast an extra 4" if it can reasonably be avoided, so I set my sights on making mine exclusively for 16" short shaft engines. Now to do some maths. My cerrent largest outboard is a 65HP Merc. Gotta figure prop diameters for thos occasions when a skeg might be partially broken off. I wanted at least a couple of inches clearance between the bottom of the prop's arc of travel and the top surface of my barrel. Then I harkened back to the 1st plastic test barrel (30G) I'd built years earlier and recalled a lesson I'd learned:
Add ~1/2" to whatever number I'd calculated to adequately accommodate short shaft engines. <-- The reason for this comes later.
6. Having arrived at my magic number, I then set about to plan the single overall sawzall cut. Enter: more compound curves to mark and to plan for. See pic #2
7. The evil mounting bracket = MORE &#%@* compound curves!
Unlike the steel barrels, the plastic barrels have curved sidewalls. <-- You gotta take that into account when cutting the two 2X6's that mount to the barrel's interior sidewalls. Plain 90 degree cuts of the curves just won't do. Upon assembly & lag bolt tightening, stuff will warp and your patience will break. So cut the curves on enough of a diagonal (maybe 3 - 4 degrees?) so that when you manually hold them in place in turn, they fit snugly to the sidewall and REMAIN... flat & level crosswise! One more thing: one of these two 2X6's will be slightly wider than the other because it's gonna hafta fit a larger diameter circle since it'll mount about 2 - 2-1/2" deeper into the barrel. Remember that the the transom at the back of the boat isn't straight up-and-down. It's sloped. You'll want to nearly precisely match that slope when it comes time to mount the 2X8 the engine's transom clamp is gonna clamp onto. See pic#3 for the two 2X6's
8. Mounting hardware: I learned the hard way to avoid the use of cheap galvanized 1/4" lag bolts. <-- That goes for 5/16" versions too!
You want this beast to last, right? Then spend a buck. Go with stainless or even grade 3 or grade 5 hardened stuff. The 3 and 5 is stronger than the stainless. And still won't rust much [in fresh water]. It's a good idea to have either some BIG C-clamps or at least 18" woodworker's gluing clamps on hand for pilot hole and clearance hole drilling. After carefully calculating and marking where each and every hole in the barrel is to be drilled (center-to-center & evenly spaced!), locate the 2X6's where you want 'em and clamp them firmly in place. BTW, that bottom 2X6 should be the first to be drilled for because......... you'll probably gonna hafta do some jury-rigging because none of your clamps is gonna have a deep enough throat. I ended up using grade 3 1/4" X 2-1/2" near the outside edges of the 2X6's and 3" versions nearer the the center of the 2X6's. <-- I wanted maximum wood depth 'bite'. Hardware also included 2X stainless flats, and 2X stainless locks to help insure snugness even as the wood dried and shrank over time. Can't use lags to attach the 2X8 to the 2X6's because the heads and washers will protrude too far and interfere with the transom clamp smoothly sliding down onto the 2X8... UNLESS........ you wanna use a spade or Forstner bit to counterbore into the rear surface of the 2X8 to allow the lag bolt head and the flat under it to lie below the rear surface. And remember, you're going to want to drill STRAIGHT into the center of the wood so it'd be best to use a drill press for the Spade bit/Forstner bit work. The order for drilling the barrel is: clearance hole 1st, all the way to the proper depth into the center of the 2X6's, followed by clearance holes all the way through the barrel and just part way into the 2X6's. If you're unsure about the proper approach to sizing pilot and clearance holed, do an online search and find explanations with illustrations that make the concept clear to you. I chose the K.I.S.S. approach: I used size 10 (I think - larger diameter is better than smaller), hardened round head deck screws with Torx drive and added stainless flats slightly larger in OD than the the OD of the screw head - knowing that with the Torx head I coule drive the washer and screw head down into the wood far enough for it to finish up with a flush surface for the engine's transom clamp to slide down onto. See pic #5.
Selecting the wood. You're going to all this trubble, so don't be a pootiehead and cheap out with this important issue. Go with pressure-treated. Period. As clear as you can get it. No knots if they can be avoided. CERTAINLY no knots on top of bottom corner/edges, and you're a regular bonehead if you locate a knot where a lagbolt or deck screw is gonna be located. Knot material provides a sub-standard screw thread anchor material, plus knots eventually dry out: *POP* Out comes your fastener! <-- Don' DO dat!
If you can *NOT* lay yer mits on suitably clear source of pressure-treated and you're reduced to settling for something with the beginning of a split, DON'T PANIC! Gitcherself some 1/8" thick angle iron, say 1" X 1". Cut it to two equal lengths with an eye toward each length
just slightly shorter than the top-to-bottom dimension of your 2X8. Use a jointer, router, table saw, circular saw or even a chisel, and create a channel on each rear face of your 2X8, running up-and-down, so your split-stopping bolsters can be flush-mounted - again... to the REAR surface of your 2X8. THINK... about what kind of hardware you're gonna use to secure those lengths of angle iron. I chose 1/4" flat head 1/4-20's and countersunk (<-- NOT the same thing as "counter bored"!) to rear-facing surfaces of the angle iron. I used 2 bolts - 1 top and 1 bottom at each end. Flats and elastic stop nuts on the front surface of the 2X8 finished the job of bolstering against a potentially widening split.
One more word about PLANNING on where to locate all the mounting hardware: Fasteners coming toward each other from opposite directions CAN (and DO) run into each other.
When it gets daylight out I'll take a couple of pics of my test barrel and post 'em here.
Have fun!
Pic #1
Pic #2
Pic #3
Pic #4
Pic #5
My test tank pic#1 <-- Lotsa compound curves. I messed up and failed to leave that 2" wide arc of the top attached to my splash guard. Afterthoughts R' Us! My lagbolt mounting pattern shows up, as does that "Magic" lip that makes for the small parts and hand tool tray. You can see 1 of the "floppy" OMC & Chrysler type transom clamp handles. That brass-looking thingy is the barrel's new drain stopper. I should mention a drawback this kind of stopper presents: With use, the oil that gets in the water will eventually cause the rubber to swell up, rendering it near impossible to remove without either breaking it or unscrewing so you can push the rubber part INSIDE the tank - where it and the brass washer and brass nut are all gonna get all icky from the inevitable oil sludge..
My test tank pic #2 <-- Here's a better shot of the brass stopper and some small parts sitting on that "Magic", semi-spill-proof shelf. I fergot a li'll detail: I never got around to adding a pair of raised lips onto the REAR of the shelf. The blanket's there to help contain the heat from a heat gun since I have someone responding to my Craigslist ad today. It'll start 1st or 2nd pull in civilized weather, but right now it's only been a few degrees above freezing.
My test tank pic #3 <-- The drain hole and it's new brass plug. After the weather turns decent I intend to get rid of that brass plug and install a durable ball valve.
My test tank pic #4 <-- Does not have the spacing I now recommend between the top & bottom 2X6's. This one has more fore & aft wiggle than I want, especially when I'm cranking a larger or tighter engine.
Whale tails are your enemy... when it comes to this kind of test tank. Remove it before or cuss yer brains out later.You're going to find it difficult enough already to manipulate the lower unit (orienting it left-right) to persuade it to drop straight down far enough to rotate the lower unit 90 degrees so it's pretty well centered in the barrel. Also, BEFORE you whip that outboard up to drop it into the tank, take the time to ENSURE:
1. That both clamping screws have clean and lubricted threads so you can easily run 'em all the way in and all the way out. You'll want 'em all the way OUT as you drop the engine down into place.
2. That the tilt lock/release operates smoothly & easily. <-- That goes for any tilt reverse locking rod, whether it has a clevis and is removable out one side or the other, or is a permanently-installed, spring-loaded jobberdoo.
There ya go. Piece o' cake.
Oh! LOOK!
It's beer-thirty!
