I have a fiberglass SOT and I would like to install a back band on it. The boat doesn’t have any eyelets for the back band, so it looks like I will have to install them myself. This is a little scary to me since I have never worked with fiberglass. Does anyone know where I can find some instructions on how to do this? What sort of eyelets and method of attachment to the boat work best?
Thanks much for any help!
KEAGLE-IT’S RELATIVELY EASY
to install eyelets/padeyes/clips etc.
You can pop rivet (probably the most commoin method), or screw-in, or bolt-on.
The latter two are better, strength-wise, but may not be possible. To either screw-in or bolt-on in fiberglass, you need to be able to reach the business end of the screw or bolt -in the former, to put a backing (block of wood or plastic) in place to enable the screw to find purchase and spread the force over a larger area, or to hold a wing anchor in place (but not as good for strength and force dispersion as the backing block), or for the latter, to hold a washer and the bolt in place.
The most common approach is to blind pop rivet: drill a hold, place the rivet in the riveter (a tool you buy at the hardware store, along with the rivets), put a dab of good marine silicone sealant in the hole, insert the rivet in the hole, and squeeze the rivet home, snugging it tight.
For whatever you do, Al or SS are the ONLY fastener materials of choice.
You’ll find most glass kayak maufacturers, as well as those who produce plastic & composite boats, all usually attach padeyes, clips, line guides, and other deck hardware via rivets.
For a good explanation, check out
http://sit-on-topkayaking.com/Articles/Instruction/BasicMaintenance.html
over at Tom Hotley’s SOT site -it’s a good intro to what you’re looking for, and has some helpful illustrations.
Hope you have a fine, easy installation and produce a fine setup. Once it’s done, (and it maybe warms up a bit?) get out there, glassy or not, and
Paddle on!
-Frank in Miami
What boat?
Can be trouble on many. Odds are with an SOT you’ll have to attach into blind holes - and the layup may not be up too it.
Seat straps can take some force, and last hing you want is to rip big holes if the fittings rip out.
One way to strengthen is to drill, and force a blob of epoxy in. Gives you a bit more to screw into.
Boat info should help you get nore specific info.
What Boat?
Just curious which fiberglass SOT you have. I have a kevlar Shearwater and a fiberglass Revenge.
I have gone abolutely nuts with the rivet gun on my plastic SOTs with good results.
The Revenge needs major outfitting, and I too am a little reluctant to go to the gun with it. Trying to figure out how to use the screws holes that are already available. It has big hatches fore and aft, but no access at all in the cockpit.
Thanks!
Thanks for all the good info!
I have a Futura Tandem Sport in fiberglass. There are some eyelets already in the boat, but not for seats or backbands. The existing eyelets appear to be bolted and also glued on with some white looking compound. That is why I was a bit reluctant to try the rivet gun all by itself. There is no way to use bolts because I can’t get to the underside.
So I suppose some rivets and epoxy might work best? I have done some repairs with my tupperware kayaks, but fiberglass seems like a different animal.
Thanks again for any help!
Call Vince at Futura
Vince Darwood
Futura Surf Skis
578 Mira Vista
Oakland, CA 94610
(510) 465-0170
Let Me Know!
If you get any good info, let me know!
Fiberglass
If the fiberglass is thin, the folks at West Systems Epoxy recommended
- Drill a hole
- take a small piece of sponge and soak it in epoxy
- Push the sponge in the hole. The blind side of the sponge will expand to provide support.
- When the epoxy cures, cut the sponge flush with the surface.
- Drill a pilot hole and insert screw.
Futura’s Reply
Good suggestion!
Vince is a very helpful guy. I emailed him, and this is what he had to say:
“Good to hear you are enjoying your Tandem Sport. It is a fun boat.
Are the seat bands you want to install attach with four hooks or two hooks?
Do you have side handles installed?
It is very important to have a wood backing on the inside of the deck if you intend to depend on the back band. Our tests showed each eyelet needs to be a three hundred pound test in order to survive a wave breaking onto your deck while you are paddling it. Some people might use sponges or pop rivets which may provide “enough” resistance for their type of paddling. I recommend you install the eyelets so that anyone who may paddle the boat anytime in the future would be safe.
Pop rivets will break through at about 100 psi (12 year old research). Well nuts seemed to perform better and broke through at almost 200psi. 200 pounds doesn’t go far with an adult man sitting in a boat wake with his legs pressing against the pedals. I’ve attached an image of the well nuts. We have used them successfully to attach some accessories.
If you can get away with a two hooked seat-band you may be able to hook them onto the side handles. Those side handles exceed the 300psi test with marine grade plywood on the inside.
The only other advice I have is to concentrate on your posture. You can go for hours providing you sit straight with a slight forward lean. Keep your paddle at least chin high and your elbows shoulders high . Shorten the pedals an inch or so. That will help you push you hips further back into the seat. When you stop for a break you may consider dropping your feet into the waterand leaning forward. That will help you stretch your back.”
That was very helpful. Looks like the best way might be to use well nuts, since I can’t get inside the boat to reinforce with plywood, and I don’t have side handles. I will let you know how it works out.
The best points
he made were about the posture. Seat backs can really interfere with learning good paddling posture. They treat symptoms, not cause - and can aggravate things long term.
Once you are upright or slightly forward the weight is inline and the back stress removed. Then the rotation while paddling serves as a continual stretch and massage.
Technique isn’t really about speed, it’s about the least stress and most efficient application of power/motion.
Paddling has actually resolved some lower back issues I had (once I stopped leaning back into a seat). I use a low narrow backband (more a hip band) in my sea kayak. The seat pan on my ski gives similar low support.
Check your foot position as Vince recommended too.
My understanding of well nuts was that you need to access from both sides. They are bigger than the hole, no?
Well nuts
Thanks for the input about posture, etc. I am
going to try those things.
As for well nuts, ScupperFrank gave a good link:
http://sit-on-topkayaking.com/Articles/Instruction/BasicMaintenance.html
You can use the well nuts several ways. If you
can’t get access to the inside, you drill a hole
big enough to take the small end of the well
nut, insert the nut in the hole, and then screw
into the nut. The nut expands on the inside, holding things on. Sounds pretty clever. I ordered some hardware from the site. I’ll let you know how it works.
Back pain
Interesting aside:
I wanted to try a back band on my ski because last time I went out I sprained my back trying to catch a wave that was a bit too fast.
When I mentioned this to Vince, he said that last year he used to do 500 pushups and 1000 situps a week. This year he is not doing that, and now he is also having back pain. I guess he has good technique, so that is very interesting!
Greyak— I’m trying no back support at
all in whitewater kayak, at least as a conditioning and boat-control measure. I’m so big that in some boats, a seat back or a back band can be a serious impediment to wet-exit. Also, in ww boats, fore-aft body weight is a major element of boat control. Leaning back unloads the bow for turns or to help the flatter part of the underside plane on a wave. Leaning forward helps the bow track straight, and may help the stern spin around on the surface. The best place to bend the back is at the hips, and when one uses a seat or a backband, one ends up bending back in the upper lumbar area rather than from the hips.
I need to go read what Scott Shipley says about backbands in “Every Crushing Stroke.”