tank hatch, stripped bolt.

[txav8r]

In rereading this thread and considering all that a few have had to go through to get these things out, I wanted to offer a few other thoughts. I am assuming that the that the "steel ring" that @upperdeck mentions that is glassed into the face of the fuel tank floor hatch is actually aluminum, and the bolts are stainless steel. It is common for a type of galvanic corrosion to set up between stainless and aluminum, and I expect that is the white powder or residue on the bolts helping to freeze them in place. The other side of the equation is having a good "bite" with the tool to remove them. I suspect that Yamaha shifted from phillips early on to the square drive heads to try to eliminate much of this. The problem is that a fastener of that size binding will almost prevent anything from removing it without wallowing the head of the fastener. I would suggest using an impact wrench to help remove the frozen bolts but by the time you know they are frozen, the head is probably already wallowed out some.

 

[upperdeck]

Absolutely NOT aluminum. I'm building an aluminum airplane, I know what aluminum is, and this ring is not it.

 

[txav8r]

Ok, good to know.

 

[txav8r]

If it isn't stainless steel, that is much of the problem then.

 

[Scottintexas]

I would not disagree with anyone's ideas on the problem of these bolts but the ones that gave me trouble had a white chalky substance on them leading me to believe they used some type of locktite when installing them,

 

[txav8r]

maybe try a magnet down in the hole, if it doesn't attract, it is either stainless or aluminum. It isn't likely that Yamaha absorbed the cost of fabricating and producing a stainless steel flange for the fuel tank hatch compartment...but I have been wrong before. And I would think that with the water that it is exposed to, that if it wasn't, it would rust big time. So while I don't know the absolute composition of the the metal involved, I am just wondering how it could be mild steel and not see much more corrosion than has been reported. My bolts never froze, and they didn't have any of the white chalkiness reported by others. I didn't use anti-seize on them either, and I had my cover open no less than a half dozen times, probably twice that. Again, I don't know, just going on logic here, and that may be a big mistake. But I have a good deal experience with metals as well, and I have been mistaken before.

 

[waterboy]

I have 2 of my bolts that have nothing they were attached to. No metal ring, no embedded nut, nothing but an empty hole. I have not investigated the others to see what they attach to but I did repair the 2 "bad" holes.

I drilled out the hole that was there and epoxied in a SS nut into each hole. My drill hit nothing but gelcoat and fiberglass in drilling this out. I can say for a fact that there is no metal "ring" around this base for the hatch (at least in my series of boat) and better yet no wood.

 

[Seadeals]

well, bolts won the battle but lost the war. Had to drill the heads off to failure, then pull the cover. Fortunately the bolts are long enough to be able to get some vise grips on them for removal....and salvage the threaded holes.

I did the same a few years back. If they are REALLY stuck, might be worth cutting to the chase. I ordered new bolts and some plastic sleeves and now have extras if needed. Luckily they all came out fine a few weeks ago. I was pulling the floor to run a new transducer cable. I think I will pull it at the end of every season now. Having the tank exposed when topping it off for the winter was great for getting just the right amount of fuel in there... plus I got all the Doritos out of the cracks!

 

[upperdeck]

I should clarify... While hacking away at the floor hatch, I tried tapping out the screws by all means I could think of. I finally came to the conclusion that I was going to cut out a chunk of fiberglass that had one of the more stubborn bolts that were snapped off AFTER I removed the floor hatch. I cut several inches to each side of that particular bolt hole deep into the fiberglass. My intent was to rebuild the glass around each bolt hole. Shouldn't have been a big deal. I was using a diamond blade cut off wheel. After I got through a thin layer of fiberglass I hit metal that was sparking on the diamond blade on the cuts that I made on BOTH sides of the bolt hole. Aluminum does not spark. The metal didn't look like any aluminum I've ever seen. I will admit that I came to the conclusion that it was a metal ring embedded the entire circumference of the hatch, I didn't continue with this method after the one bolt hole. It is possible that I picked one spot and ran into metal and that there is no other metal reinforcements on the entire deck, but doubt it.

 

[txav8r]

The hatch is wood as far as I can tell and it had two metal stiffeners also across it. I know there are some sort of threads embedded in the hatch but I honestly don't know whether it is a nut or nut device, or just a threaded metal plate. I don't know enough to argue about it, but I do know my bolts never froze, were easy to remove using a #2 flathead diagonally across the square recess. There was never any white chalking and the bolts were dry. But that doesn't mean others haven't had this issue! If I knew of a totaled boat, I would look into buying the floor hatch and do some destructive testing on it. But things change year to year and model to model so I doubt I would reach a conclusive result that would translate across all models and years. My guess is that the hatch has been an evolution, because the "full" hatch didn't show up until Yamaha saw a need, and then they had issues with fasteners and improved them, and now they have abandoned mechanical fasteners for latches. I think everyone in this thread has nothing but the best intention of helping others solve their issues.

 

[waterboy]

it sounds as if you guys were talking about the hatch. My repairs were done to the "lip" part where the bolts screw into or the "floor of the boat. The hatch probably is wood and it may have a metal ring around it for stiffening. I may not have read everything close enough.

but right, either way, trying to share what I have seen and found in this section of the boat doing surgery

 

[Seadeals]

Here is a picture I have showing my fuel tank access floor bolts lined up. This is over two years after completely cleaning the threads with a brass wire wheel and reinstalling (some even new). There is definitely something buried in some of those holes that likes to grab onto these bolts. That is also my impros-refurbished impeller after 2+ years... lookin' good!

 

[upperdeck]

I was never referring to the hatch itself, but the lip that the hatch rests on.