Flush mount install

Did a quick search and didn't see any info out there so I thought I would do a quick write up. My yak came with only one behind the seat but I want four so out came the hole saw!!!
First I layed it out where I wanted it to go planning for how the inner portion would end up inside the hull. I just used the gasket to get an actual location and traced it with a marker. (Pic1)

Then I tarted the hole with the pilot bit on the hole saw .  The drill must be angled to the direction that the inner portion of the flush mount is facing. (Pic2) * tip run the hole saw in reverse if the teeth are biting too fast in the soft plastic. Also use the closest hole saw size you can find and when in doubt go smaller you can always file it to make the hole larger.

Now test fit the flush mount and file as necessary checking for fit often. (Pic3-4)

Once it fits snug with a 3/16 bit drill one of the holes and insert a rivet to keep the holder from shifting when you drill the next one. (Pic5)
 
Now add your goop and place the holder and gasket into the hole. Set in all rivets. When seating the rivet press down firmly until the rod holder is flush on the bottom until the rivet pops. Then wipe excess. I like to add a little to the rivet hole as well.

Very nice work John.What brand are they?

The larger ones in the middle are just standard size yak...something... And the smaller ones on the side are made for Viking

I don't usually wipe the excess goop off. I let it dry then exacto knife it and peel off. I feel it's a cleaner install and better seal that way.

I could understand that, but my thought is by wiping it while wet you will push the sealant into any gaps leftover.

Hey Jon.  Are those 8"s or 10"s behind the seat?      

Eights...

 

  Did you use any sort of back up or reinforcement for the rivets inside the hull, like washers, or, are the rivets just hanging on to plastic?
 Never mind, I just looked at the pictures again, you really don't have access to reach the areas to add any reinforcements to either side.

  On my outback, I bruised my shoulder reaching through the back hatch to reach the area where I installed my scotty mount for my little down rigger.  The farthest cap screw was juuuust in reach, I mean, just, with the nut balanced dangerously on the very tip of my finger, and I also have a 3/16" steel plate drilled to match the bolt pattern of the scotty mount for reinforcement.  Took a few attempts to get everything attached and tightened up.  Rivets would have been quicker, but the SS hardware will hold fast for a while!

Yeah if it were an option to use a nut and bolt I prefer that option but on this kayak there is no access behind the seat. The long split rivets spread the load as much as possible. If they pull out again I will have to fab a threaded backing plate and glue it in place.