Adding inspection port to fiber glass tanks.

My new to me 81 Hardin has original Fiberglass tanks.
Would be nice to have a clean out and inspection port. Hoping someone on the site might have done this and can share how A person can do this?

Thanks Ed

You can buy inspection plates plastic or metal and install them.

But if you want to make one yourself here are the basics on how I did it:

Cut a hole where you want the inspection port.
Glass a flange to the piece that was cut from the hole.
Once cured put the hole piece with the new flange back in the hole and drill holes for bolts around the flange.
Remove the hole piece and Epoxy stainless steel bolts from inside the tank with threads on the outside.
You now have a cover that you can remove and replace.

Seabuilt makes access plates. Not cheap but well built and relatively easy to install.


Seabuilt - Access Plate Systems

Inspection

Thanks Larry
I see you are at Friday Harbor. Do you also live on the island or just have your boat there? We will probably move the boat up there next summer. We have a second home over by Roche Harbor.
Ed

Ed: Hobo has been based in Florida for the last few years. We left FH a few weeks ago to head back to the heat.

Larry,
Where do you stay when up in the the northwest?
Did you take hobo down though the Panama Canal from Friday harbor?..??

Ed

Mach_cat said:

Larry,
Where do you stay when up in the the northwest?
Did you take hobo down though the Panama Canal from Friday harbor?..??

Ed

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PM Sent

GRP is almost always strong enough , but it takes thickness to be stiff enough.

I would glass on the outside of a GRP tank till it with the existing material was at least 1/2 or better 3/4 thick.

The tank wall flexing now is no problem, should it flex with the inspection port installed , you may get a leak.

I added a clean out/inspection plate to our in-keel water tank on our 1970 LeComte Northeast 38 sailboat. The tank top is about 3/8" thick originally bolted to fiberglass of similar thickness forming the tank top. Good old early '60s practice! I screwed the tank top 'permanently' in place and added a Beckson PVC access port. I've used these ports on a 1968 Flying Dutchman sailboat as well. Screwed into the 3/8" tank top and bolted to the flexible 1/8" 'glass on the FD. Bedded in 5200.

These Beckson PVC ports come in several diameters; 4", 6", and 8", if I remember correctly. Pick what's suitable for your purpose.

Entirely satisfactory.

Hey guys, you forgot one piece of critical advice - and that is..........................make sure the contents of the tank is BELOW where you want to cut the hole, BEFORE the first cut

Well I think empty is better. Do not want Fiberglass in the fuel!
Also want to clean the tank.

Brisyboy said:

Hey guys, you forgot one piece of critical advice - and that is..........................make sure the contents of the tank is BELOW where you want to cut the hole, BEFORE the first cut

Click to expand...

George, might you have learnt that sage advice by experience?

Bruce............shame on you for even suggesting it.............luckily the answer is no.