Threaded inserts for fuel tank installation

Pete,
I just checked out your link on the threaded fastners. Were you thinking of installing them in the floor and bolting down the plastic strips? I assume you will be moving the side strip further inboard due to larger tanks? I am going to do something to repair my tank chocks this spring. The forward strips pulled up from the floor on mine. I like the looks of the blind fastners and I would think they would support a large vertical pull once epoxied in place. I didn't even know such a thing exsisted. I was planning on bonding a 1"x1" strip of wood to the floor with epoxy and screwing the tank cover board into it. If you go with the inserts I would like to know how it worked for you. Thanks,
Ken
 
Hi Ken,
installing them in the floor and bolting down the plastic strips?
Click to expand...
That's the idea. When Adeline was new my fiberglass repairer warned me about water migrating down the threads into the core. I removed the screws securing the tank hold-down brackets and a number of them were quite wet. I drilled them out and dried them over a couple weeks. Then I filled all the holes with epoxy. I then replaced the brackets using 5200 and no fasteners. It has worked well for 15 years but the new tanks call for a different approach as 5200 will not adhere to Starboard. I COULD secure (with 5200) chocks made of a different material, such as teak. Then I would screw to that. However, I'm thinking that I might dry-fit the tanks and mark the Starboard hole locations for drilling. Then I would drill oversize holes and fill them with thickened epoxy. Finally, I'd drill holes into the cured epoxy and bed the inserts, again with the West System. The idea is to provide threaded anchors that are completely encapsulated and not a threat to the core. Also, it would make removal alot easier than cutting away cured 5200.
 
I have a C-Dory neighbor who had a problem with the cleats securing the fuel tanks upsetting and the screw holes for same loosening up. He drilled larger holes for the forward cleats and imbedded bolts (head down/thread up into an epoxy bed. This of course permatized the bolts in the floor and the cleats drilled to match the bolts simply fit down over the bolts and nuts secure them. He has no cleats on the inside of the tanks under the splashwell. He drilled out the old screw holes, filled them with epoxy and he placed cleats on the underside of the splashwell to prevent lateral movement of the tanks. I believe he used either 4200 or 5200 to secure the lateral cleats. Only has one year on this re-do but it looks great and he is very happy with it.

I am going to re-work mine but haven't decided exactly how as yet. Using threaded fastners, epoxied into the deck, and bolt to secure the forward cleat sounds like a sanitary way to go. For the lateral cleat, I think I'm going to borrow a page from my buddys book and stick 'em on the underside of the splashwell, thereby not violating the integrity of the hull with any more holes than neccessary.

Hey Dan........coffee is giitt'en cold! Nice pic's in your album..I like!

Mark
 
When I pulled my tanks to install the trim tabs on my 2003 22' cruiser last spring, I too discovered some soft screw holes in the deck under the starboard tank covers and cleats. Several of the screws were loose. There was moisture present in a couple of holes.

My solution was to drill out all the holes with a 1/4" bit, let them dry for several days, then filled them with thickened epoxy. After the epoxy had cured overnight, I drilled pilot holes and screwed the tank covers and cleats back down with the stainless screws I had taken out while the epoxy was still somewhat soft. The fresh epoxy took the screws well with the pilot holes drilled. When I re-installed the tanks, I used 3M 4200 and the stainless screws to secure the tank covers and cleats to the deck. So far, so good and all the screws are holding tight.

I am very glad that I needed to pull my tanks not long after receiving my boat and able to do a much better job of installing the tank covers and cleats to the deck to avoid a larger problem down the road. The factory should use some other method/technique of securing the tanks as obviously, the way they did it on mine and others did not work well!

Jim
 
For what it's worth, see Fuel Systems Photos, page 2, regarding Alma's Only. I'd tried the fiberglass bedding of screws with marginal success, and went to another approach, which has worked great over the last year, and shows no sign of movement or leakage.

Good luck!
 
Today I completed installing bolts for the fuel tank chocks. I used the method 3rd Byte mentioned. As a side note, I have a 2002 so it is not that old, but I found a lot of wet balsa in 3 of the screw holes I drilled out.
I posted pictures in my photo album. I first used a brand of epoxy which was very slow curing. For the other side I used a fast-set epoxy putty which worked better since it was thick enough to hold the bolts upright without any support. I plan to level the holes completely with another batch and bed the chock with plenty of 5200. I agree with Anchortown Jim that the factory needs a better method of installing the tank chocks.
 
Be careful when drilling those holes out. Not sure how thick the hull is in that area, probably quite thick but if you do it in the water, it could be problematical.

When installing the stainless brackets for a porta potti in my sailboat many (many) years ago :| , one Sunday morning in a military marina, I was pretty well alone in the facility. I carefully marked the places to put the self tapping screws to drill. The boat was a Venture 23, a pretty little cutter rigged thing :) and we had lots of good times on it. It wasn't balsa cored like CDs are but had an inner hull and an outer hull.

Two of the holes went fine :lol: but on the third one (of 4) , I struck water!! :smileo A stream about 12" high and about 3/16" in diameter spouted up. I felt like the kid with his finger in the dike...Apparently, the inner hull and the outer hull were in very close proximity at that point. I put my finger over the hole and pretty well staunched the flow. Now I had a problem. I was alone, nothing but a basic toolbox, a hole and a potential sinking boat.... :disgust :cry

Being an inventive sort, I put the bracket in place, drove the screw into the hole and plugged the dike...

We sailed all season with that installation and when I hauled the boat in the fall, there was the stainless screw, sticking 3/4" out of the bottom paint... I fixed it right...

So be careful if you do it in the water, it could happen to you....

Since that time, lest you think this Capt a total klutz, I've supervised replacement of both Destroyer and Aircraft Carrier Propellors underwater, that's a real challenge. Some day I'll tell you the condensate pump tale!!

Charlie
 
Charlie,
All good points. In this case I drilled out existing screw holes and was able to use the old screw depth as a guide. A tip for anyone trying this technique; I tape a strip of masking tape around the drill bit and leave a little tail on it. Gives you a quick depth guide, assuming you are sure of the thickness of your hull!
 
Hi all, Thanks for the replies. It turns out the threaded inserts I posted are extremely expensive;i.e. $150.00 minimum order. Then I Googled "Fasco threaded inserts" and found this http://www.blumhorst.com/catalina27/mas ... nstall.htm . It describes closely the method I'm considering. These inserts are available @ West Marine @ about $4.50 ea.. Any opinions, as always, are greatly appreciated. Pete
 
Pete,
I just finished redoing mine and I think the upside down bolt system is just as easy to do and much cheaper. A shallow 1/2" hole is just right for the head of a 1/4-20 SS bolt. The biggest challenge I had was running the heat lamp so the epoxy would cure due to the low temps here. Good luck.
 
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