air bag lacing

Post by **sbroam** » Thu Feb 10, 2011 5:02 pm

I finally got around to putting new gunwales on the ME I wrecked at Nationals this summer. Now to put new air bag lacing in it... I really don't care to screw 30 or so stainless or plastic eyelets into the gunwales leaving me with two obvious options

- the original outfitting had holes drilled through the gunwales with loops of cord serving as eyelets - this is what I did last time
- holes in the hull

I'm really not excited about drilling holes in either gunwales or hull but am leaning toward the latter. Any reason I'm going to regret this? Any better ideas I'm overlooking?

milkman · Post by **milkman** » Thu Feb 10, 2011 5:27 pm

I've never drilled holes in the hull for lacing, but have seen it done plenty. It seems odd to expose the foam layer with a bunch of holes that could allow the foam to wick water to a wide area and degrade the hull. In boats I've seen that have done this though, that has not seemed to be the case.

Randy Dodson · Post by **Randy Dodson** » Thu Feb 10, 2011 5:32 pm

I've drilled holes in hulls for air bag lacing on WW canoes and grab loops on touring canoes. Many many times and never had a problem.

philcanoe · Post by **philcanoe** » Thu Feb 10, 2011 5:33 pm

- To me the idea of using gunwale attachment points to hold in air bags, has the added downside of there being a single point of failure. Once the gunwale breaks the bags can lift up (away from hull) and even exacerbate hull (or airbag) damage. While the drill through and lace method seemed to be more consistent with the KISS principle.

Post by **sbroam** » Thu Feb 10, 2011 5:40 pm

... and those extra holes in my beautiful new gunwales can't help but weaken them. I was leaning towards the "holes in the hull" idea and it's nice to get some confirmation from others. Thanks!

ps - Phil - I used your approach for attaching thwarts - these being smaller dimension gunwales made that an even better idea

the Big O · Post by **the Big O** » Thu Feb 10, 2011 6:04 pm

Uhhhh.......... Huh Huh, He said exacerbate!

2opnboat1 · Post by **2opnboat1** » Thu Feb 10, 2011 6:11 pm

the problem with screwing into the rails is that if you forget to let some air out of the bags or leave it in the sun then you risk breaking your rails on dry land I like drilling through the hull Been doing it that way a long time and have never had any prob but I am deadwood

Lappie · Post by **Lappie** » Thu Feb 10, 2011 6:18 pm

On most of the boats that I outfited with wood gunwales, I use what they caled sewing D rings, they are nylon D rings with a flat tab that you usualy sew into fabric. So you can use them by drilling a small hole into the tab and then place the tab in between the insid gunwale and the hull using the screws that hold you gunwales together!
I'LL try to find a picture of it!

Bob P · Post by **Bob P** » Thu Feb 10, 2011 7:12 pm

Take a look at the PVC brackets that I glued into my Spark. (Scroll down the page.)

http://wwslalom.net/bob/spark/index.htm

milkman · Post by **milkman** » Thu Feb 10, 2011 9:00 pm

Bob,

That's an interesting setup. How long have you had that installed and used it? The reason I ask is I tried an experiment once with PVC sheets, gluing them to the inside the hull to fix cracks in the boat's vinyl. The PVC sheets ended up cracking as well--not in the same place or way as the boat's vinyl, but in their own way. I now use vinyl raft material for that kind of repair.

Smurfwarrior · Post by **Smurfwarrior** » Thu Feb 10, 2011 9:18 pm

Bob, that seat looks comfy!

Big Al · Post by **Big Al** » Thu Feb 10, 2011 9:44 pm

Bob P --

Very nifty and comfortable looking seat. Where can I get one like that?

Thanks!

Big Al

Eric Nyre · Post by **Eric Nyre** » Thu Feb 10, 2011 10:15 pm

Drill the hull

Just mark your spacing so you don't have a hole directly under a gunwale screw hole. No need to have duplicate stress points.

Contrary to a comment above, ABS foam will not wick water. The only concern with exposed foam is that it becomes stiff/ brittle with air exposure. However you already have the whole top of the boat exposed (covered by gunwales or not), and drill holes for the gunwales. You're really not adding any further air exposure damage by drilling right under the gunwales. Stiff ABS isn't going to hurt with the already stiff gunwales. Stiff ABS under the waterline where it smacks a rock instead of flexing is a whole different problem.

Bob P · Post by **Bob P** » Thu Feb 10, 2011 11:51 pm

Those brackets have been in the boat since it was new. The bottom bracket takes a lot of stress from the thigh straps. The glue let go on a couple of the early (just a piece of angle) side brackets, but nothing has broken yet. How long has the Spark been out? I got one of the first. On the other hand, I don't actually use bags most of the time. And, I've never gotten more than a few gallons of water in the boat.

I made the seat from my own mold, customized to my butt. I use a similar seat in my slalom OC-1 and C1 too. Unfortunately, I'd have to get about $120 for the bare seat in Carbon fiber, $90 in glass/kevlar. I am reluctant to lend the mold out. It's my only one.

pblanc · Post by **pblanc** » Fri Feb 11, 2011 12:33 am

I resisted drilling holes through the hull for years. Once I did, I wondered why I hadn't done it sooner.

The only disadvantage is that when lacing the air bag cage directly through the hull, it is laborious to remove it and reinstall it, if you wish to do that.

You can get around that by drilling pairs of closely spaced holes through the hull and threading a small loop of paracord through each pair of holes. The paracord loop functions like an inchworm screwed to the gunwales, and is quicker and easier to run the lacing through.

If you don't plan to remove the air bag lacing, just thread it right through the hull holes.