Sealing screws on fresh water tank cover

[smokey73]

I am having leaks from the multiple screws that hold the tank cover on the port water tank.

I know this is a common problem on the Hunter 40.5 and possibly other similar designed water tanks. What seal around the multiple (probably 40 or more) screws that hold the tank lid on do you recommend. It needs to be flexible since there is some flexing on this tank.

 

[dlochner]

Try a thin sheet of neoprene. Also do not over tighten the screws, that can cause inspection ports to leak.

 

[Leeward Rail]

Try a thin sheet of neoprene. Also do not over tighten the screws, that can cause inspection ports to leak.

We used rubber sheet on our freshwater tank. I got the rubber from a landscaping store. Meant for building ponds. Available in a few thicknesses. Been using it for all sorts of things. Easy to cut and has a 50 year expected life according to the mfg.

That said, our tank is fiberglass so it may not flex much compared to whatever the Hunter tank is.

 

[FastOlson]

Hunter used to use aluminum for all of their tanks, which was a testament to the efficacy of a vendor paying for a LOT of liquid lunches with the company management. Sadly.
I have found that thin (but quite adequate for strength) metal, SS or aluminum, really benefits from having a ring welded on the top (or inside, before being closed up on all seams). There needs to be a more solid clamping surface to hold that gasket. There are several vendors for these, and they use a 'folding' ring to go inside the tank opening for retrofitting tanks.

 

[Peggie Hall HeadMistress]

A thick rubber gasket is the best choice, and you can buy rubber gasket material in a range of thicknesses at any big box or good hardware store.

--Peggie

 

[Rick D]

If you are talking about the screws themselves rather than the lid (which was in my case), I used Boatlife Life Seal which took care of the issue for ten years. Boat Life Seal

 

[smokey73]

If you are talking about the screws themselves rather than the lid (which was in my case), I used Boatlife Life Seal which took care of the issue for ten years. Boat Life Seal

My leaks are from the screws themselves and I used Boatlife Life Seal on the starboard tank. Just wanted to see if there was a better way. No leaks in about 10 years on the starboard side so I think I'll go that route. There are no leaks from the lid-tank joint.

 

[DArcy]

If the screws go through into the tank then water can get up through the threads. If the gasket is tight around the screws this may be enough to seal them and keep the water in but if not then sealing screws may be beneficial. They have an O-ring under the head that seals to the surface. Don't use washers when using sealing screws as this will provide an unsealed path for the water to get through.

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