Installing an Inspection Plate on a Plastic Fuel Tank
- Thread starter Nodak7
- Start date
These guys make a purpose built one.. Fabbing one is not hard either..
Thanks kloudie! This was helpful. I am looking at the Seabuilt cover now. It says that it will work with a poly tank. Now I am wondering if there are any baffles in the tank.
If you have a poly tank there will be no baffles because of the fabrication process. As far as I know it is technically impossible. I have installed an inspection hatch in my tank, used a UK supplier, will look up supplier name.
Edit: The supplier is Tek-tanks.
Edit: The supplier is Tek-tanks.
I installed a plastic removable panel on my plastic tank 11 years ago. When cut open the tank I was horrified by the amount of debris there was in the tank. I siphoned the diesel fuel out when the boat was on the hard. The last gallon looked more like it came out of the house eave trough that a fuel tank!
I cut the square hole with a sharp utility knife and cut a piece of 1/8 thick Lexan an inch bigger in both length and width. Then I drilled screw size holes 2-3 inches apart in the panel. I set it in place over the cut opening in the tanks and marked each hole. I drilled the tank marks- make sure the hole size is the size if the shank in the screw so the screw threads create threads in the tank plastic. Screw in the screws so the holes are threaded and plastic bits are screwed out. After doing this, very thoroughly clean the tank using a lint free cloth damped with diesel so all the bits from drilling get cleaned out. I used 3M 4000 compound to seal the panel.
Have had no problem with it. If you do remove it- I have once- be careful to lift it so bits don't fall in the tank.
I cut the square hole with a sharp utility knife and cut a piece of 1/8 thick Lexan an inch bigger in both length and width. Then I drilled screw size holes 2-3 inches apart in the panel. I set it in place over the cut opening in the tanks and marked each hole. I drilled the tank marks- make sure the hole size is the size if the shank in the screw so the screw threads create threads in the tank plastic. Screw in the screws so the holes are threaded and plastic bits are screwed out. After doing this, very thoroughly clean the tank using a lint free cloth damped with diesel so all the bits from drilling get cleaned out. I used 3M 4000 compound to seal the panel.
Have had no problem with it. If you do remove it- I have once- be careful to lift it so bits don't fall in the tank.
senang, thanks! This is a much better idea! Unfortunately there is no US Distributor! I am checking to see if they will ship to the US.
Hi Nodak, they have 2 models the big one they sold me and the smaller ones. Like Richard said, the trick is to screw the bolt in a poly hole that is in fact to small. Tek Tanks instructions are to screw the bolt from the inside of the tank. That is impossible because you can not apply enough force. So I drilled bigger then the instructed size. Now you can get the bolt in the hole, but you have the problem of holding the bolt while tightening the nut. I created 2 flats on the end of the bolt that I can hold with a plier, problem solved. They supply special washers to go on the inside of the tank and a cork seal for the outside. I applied Hylomar Blue and I guess I overtightened the seal a bit, but no leaks!
Hi Nodak7,
Here's the link to how I did mine. Pretty easy job.
Hunter 34 Owner Modifications and Upgrades
Hunter 34 Owner Modifications and Upgrades
hunter.sailboatowners.com
Allan
Nice write up Allan! Thank you! What did you do with the old fuel?Hi Nodak7,
Here's the link to how I did mine. Pretty easy job.
Hunter 34 Owner Modifications and Upgrades
Hunter 34 Owner Modifications and Upgrades
Allan
Before I started the project, I made sure I had used the majority of the fuel. I bought a filter/funnel from West Marine. After pouring the fuel between two Gerry cans twice, I filtered it one more time back into the tank. I added 5 more gallons of fresh diesel with Biobor and ran it down to nearly empty before filling back up completely with all new. We have a collection bin for used absorbent pads. After wiping out the filter, I combined them with the ones from cleaning the tank and put them in the bin.
Baffles in. poly tank are NOT impossible. They are actually added in during the inflation process. Poly tanks with baffles are easy to spot. The tanks are not smooth. Each baffle point looks like a channel that usually runs up one side, across the top and down the other side. This channel is often the area that anchoring straps are placed..
I would NOT cut a square hole in any tank. The code requires that the corners be rounded to reduce stress, and yes, I've see square holes crack in the corners (steel, aluminum, and polyethylene). Square repair patches are also forbidden, because cracks can start in the corners. With a round hole, stay 2 inches away from any sides or corners.
I hope it is obvious that all of this goes triple for gasoline tanks. The certification will almost certainly be voided. But there is no need on a gas tank.
BTW, if you want to sump water from a gas tank (or diesel, but especially gasoline), the safest commonly available tool is a non-electric vacuum extraction pump. However, stop when you get to the gasoline; pumping a significant volume of gasoline can lead to static build-up and boom, since the hoses are non-conductive (proper gasoline suction hoses are made of a conductive rubber and grounded through the embedded wire--this is what you see at a gas station). I once did an accident investigation where someone used a non-conductive hose to pump gasoline. Static from the gas moving through the hose was the ignition source.
(Tank inspector)
I hope it is obvious that all of this goes triple for gasoline tanks. The certification will almost certainly be voided. But there is no need on a gas tank.
BTW, if you want to sump water from a gas tank (or diesel, but especially gasoline), the safest commonly available tool is a non-electric vacuum extraction pump. However, stop when you get to the gasoline; pumping a significant volume of gasoline can lead to static build-up and boom, since the hoses are non-conductive (proper gasoline suction hoses are made of a conductive rubber and grounded through the embedded wire--this is what you see at a gas station). I once did an accident investigation where someone used a non-conductive hose to pump gasoline. Static from the gas moving through the hose was the ignition source.
(Tank inspector)
For a fuel tank I used the Seabuilt inspection port as I installed a fuel gauge sender on it at the same time. Took 3 hrs and the gasket is fuelproof --pun intended. For my water tanks I used transparent access panels, Beckson, which come in several sizes, depending on how much our arm/shoulder you want to get in there, Sealing the rim and screws with 3M 4000 will work, but rough up the rim of the hole with 200 grit and clean with lacquer thinners before sealing and securing. No leaks and a clear view when filling...….Also makes for annual cleaning, scum removal and sanitizing sooooo much easier.
Thanks for the professional advice! I thought the same thing when I saw the picture but your standing as a tank inspector will certainly hold a lot of weight! You see this type of stress and potential for cracks in every type of material. Look it up, that's also the reason the windows in aircraft are round(ed).
As an FYI, my father and I cut out a fuel pickup tube in poly tank that was in an older Chriscraft bow rider. We used it also as an access panel to clean out the tank. We fashioned it very similar to Allen's on his h34.
When I had fuel problems I used a 12 volt pump to empty the tank into a Racor filter into jerry cans
and did it through the fuel gauge plate and after all fuel was gone I used a snake camera that hooks to a cell phone or tablet and found a large mass of gunk that after 11 years had built up way down the back and needed the camera to find it.
I used a small shop vac with garden hose on the end suck out the tank very clean and have had no problems 2 years now.
My fuel tank is under my bed so preferred not to add any openings worried about leaks and now add bio something and runs great and also took apart my Racor 500 and cleaned it like new.
Nick
and did it through the fuel gauge plate and after all fuel was gone I used a snake camera that hooks to a cell phone or tablet and found a large mass of gunk that after 11 years had built up way down the back and needed the camera to find it.
I used a small shop vac with garden hose on the end suck out the tank very clean and have had no problems 2 years now.
My fuel tank is under my bed so preferred not to add any openings worried about leaks and now add bio something and runs great and also took apart my Racor 500 and cleaned it like new.
Nick
Well FYI I did install a Seabuilt Inspection plate on my Fuel Tank. When I opened the tank I was surprised by the black particulate in the tank. Nothing serious residue from the fuel. No biologics though. This will become an annual maintenance item from this point forward. Easy install and relatively easy project. Just had to pump out 45 gallons and replace it. Using a portable fuel filter! Piece of mind now when in rough waters. Thanks for all the suggestions!
