Gas tank hatch repair

Fixit

Fixit

Well-Known Member
My gas tank in the boat is under a 34x33" section thats screwed down to the deck.. this sept in bamfeild i noticed that it had become pretty spongy.

so i removed the 10 screws, cut out the sealant around it to inspect the hatch, found out the two access ports for the fuel sender and filler hose were jig-sawed into place and left with bare plywood edges :( wet rotten plywood that oozed horrible smelling black water

whats my best plan of attack? ive got a friend with all the fiberglass supplies... resin, mat, weave, rollers etc
ive been told to grind down the backside and lay up more glass and wood but im not sure if theres a special way to do it???
 
id love to get rid of both the access/inspection ports, but im not sure how the best way to fill them in, and have a close color match, looks like ill need to redo the non skid too, whats a good product for that?
 
I would just start off fresh. New piece of plywood and new inspection ports fiberglass both sides first cut out the holes and glass the raw edges. Drill all your holes to hold it down over size and refill with glass and drill proper size holes. Better yet get a piece of aluminum and cover the hole.
 
You want to be able to get into those 2 places thats why that hatches are there looks like waters been going past it id also start from new as wet wood sucks , also sika wont really stick to wet wood. get new plywood cut out hatches seal it all especially end grains and holes, when putting new hatches in sika where it sits screw it in THEN put a bead all the way around the hatch then use a good hard grease on threads of the hatches that should solve your problem..
just did this with my boat... have fun

wolf
 
checkerplate alu IMHO, with new access ports..
 
ive got access to some foam board (designed to be used as a part of fiberglass lay up). it might be too thick for my application though, ll have to check.

should i build a mold to make a from scratch replacement? or just lay up over the foam board and then gel coat/ non skid?
 
mbowers said:
Leave the inspection ports as you or next owner may want them and legally required to access fuel fittings at least in US.
Click to expand...

i didnt know this, where can i find out more about this requirement? does having the hatch screwed down mean its not accessable?
 
Looks like a simple square panel. I wouldn't bother with a mold. Just a plywood layup using marine grade or baltic birch plywood. You might want to consider using epoxy instead of a poly resin. Probably not necessary to use a structural cloth like woven roving or 1708 but a few layers of 1.5oz CSM (chopped strand mat) would be required. Sand and then gel coat or nonskid on top. Cut the access holes first and glass them as well sealing all edges and as mentioned drill the mounting holes oversize and then glass and re-drill.
 
Fixit said:
i didnt know this, where can i find out more about this requirement? does having the hatch screwed down mean its not accessable?
Click to expand...
Screwed down is fine as long as you don't have to cut out panels. Don't need to inspect all the time but access is always good. I'll try to dig out link for US regulations..
 
Oh and for non skid I really like kiwi grip: water clean up and you can make a really aggressive pattern that's grippy but not abrasive in the same way as sandpaper
 
This past year I had to do some work to my gas tank which meant cutting up the plywood floor over the tank. When I put everything back together this time I decided to glass the plywood cover that goes over the entire tank and not bother with the access hole. The plywood cover is held down with 10 screws if I need to gain access to the tank or fittings in the future.
 
i was just reading up on kwik grip, seems like a good product, how durable is it? can i power wash all the blood n grime off it?
 
I put it down on the last floor in my boat and will be reapplying it when the new floor goes down this spring.It's extreamely durable and had no trouble power washing or aggressively scrubbing it with a deck brush.As mentioned earlier it can be applied very aggressively with high peaks for great traction ,the sun doesn't seem to have any effect at all
to it,and it cleans up when still wet with plain water.Great product and highly recommended.
 
Spent some time working on the gas hatch

I've decided to just re core the existing hatch so it will match the rest of the floor

Got the angle grinder out and cut the cap off, exposing 25, 6x6" 3/4" plywood squares?! I guess it's cheaper to do that then cut a solid piece? Anyways... Wood was soaking wet the hatch weighed 39 lbs!

Got them all pried off, next I need to grind it down clean to take a few layers of mat...


IMG_2134.JPG IMG_2132.JPG IMG_2129.JPG IMG_2131.JPG
 
did some grinding outside when the rain stopped for 1/2 hour, and cleaned everything up with a palm sander. Im amazed at how flexy it is with out any core. Ill have to pay attention to keeping it flat when i lay up the new core. waiting to hear back from a buddy to see if he has any foam core left over from his last project
 
Whether you use foam or plywood ,I would suggest you don't apply it in one piece.It will be much stronger if you apply 2 -approx. 6" outside and a middle piece and glass them in.Then fill in the 2 other pieces and glass over entire bottom.If you end up using plywood put a coat of resin on and let cure before you bond it to the fiberglass,otherwise it will soak up your bond coat.Plywood is fine as long as it's sealed everywhere,I suspect your access holes didn't get sealed properly and the plywood end grain sucked up rain water.
 
so your saying lay up a foam core - start with a doughnut, then add a timbit to the middle?

is that right?

ive also heard to drill lots of holes in the core to allow the resin to ooze out if theres excess
 
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