Accessing backing plates in Infusion

Has anyone accessed their cross beam backing plates in their infusion?
Are they fiberglassed in?
Are the bulkheads in front or behind them? Front and rear beam.
I'd really love a layout plan of the bulkheads but last time I asked Nacra they didn't have one.
Trying to figure out if I put an inspection port behind the crossbar if I could access them.

might be able to get in there with a snake-camera

they are laminated into the beam landing.

why would you want to access them anyhow??

If you tap on the hull with something like the handle of a screw driver you should be able to determine the center of the bulkhead, like finding a stud in the wall.That is providing it's still attached.

I doubt your going to want to cut a hole in front of the beam. I've dealt with this ( not on a Nacra) by going through the port behind the beam. Take a dremel tool with a spiral cut bit and cut just the corner of the bulkhead out. Take as little as possible. You should be able to get to it. After your done you can glass the corner back in.

'Cause he's retarded.

No the guy who chose to put aluminum backing plates for steel bolts is the retard!
One of my front beam bolts stripped and ever since the boat has not felt as stiff. It stripped because the threads were somehow damaged on the bolt, I barely tightened the bolt but I didnt notice the threads were damaged until it was too late. I was able to upsize the bolt and it holds at the factory torque setting (but I do tighten it a bit tighter, part of the issue) but I'm not sure whats up.
Since they are laminated in it seems like it'd be a huge nightmare / impossbile to get them out... but if I could I would replace them with stainless steel backing plates in a heartbeat. AHPC boats have stainless steel backing plates, I think Tornados do too, not sure about Hobie.... but it just doesn't seem like a good idea to me to put aluminum ones in there!

The steel works ok with the aluminum if you use something like Tef Gel. The other thing is any time you remove the bolts you should run a die over the bolt and a tap through the plate.

Tornado's have a Helicoil in a epoxy bed. That's something you can do with yours. Just put it in with some red loctite and use the tefgel.

Welcome to the world on NACRA!!!!!!! Has a similar problem with the 5.8, the first time re tapping the thread worked, second time I went to the helicoil for one of the bolts worked like a charm.

Good luck.

Oh! And don't mind Team Chums, its turrets you'll get use to it in a while.

The alloy is for sure the best solution.

If you have a stainless steel plate and a stainless bolt.... That's a world of trouble when it seizes up.

Just pop a helicoil in there, takes 2 mins and works like new.

Don't know the layout but you can also use G10 as a backer to reduce corrosion issues.

Note to boat builders... Tef Gel is your friend, use it!

The thread is broad enough on the beam bolts that waterproof grease is sufficient to prevent any corrosion issues.

tef gel is awesome for the finer threads normally used in rigging terminals.

I use Tef Gel on every mounting bolt where I have dissimilar metals, just cuz... And actually I prefer Lanocote on rigging screws, its not as sticky as Tef Gel, and doesn't seem to attract as much dirt. I live in a pretty cool environment, where Lanocote stays very viscous.

BTW thanks for doing the Racine boat setup/technique videos Macca. They are very helpful for those of us new to beach cats!

I just did the talking!! TEH is the real champion of the video's!!!

Beam bolts siezing and threads stipping are not a Nacra thing. I have owned plenty of Hobies that have done the same thing. The real issue is not the material being used but assembly of said material. As already mentioned lubrication is your friend. The heli coil is the way to fix this issue. Cutting a hull in the deck in my opinion is always the hail mary last resort option.

Agreed. And there are advantages and disadvantages to using either stainless steel or an aluminum backing plate.

With aluminum, you have the dissimilar metal galvanic corrosion that can be lessened by using a proper goo. The failure mode is that the plate strips out and you can use a helicoil to repair it.

With stainless steel, the failure risk is less but the penalty is more severe. Galling of the threads can happen from over-tightening, overheating (spinning the bolt too fast with a tool), or repeat motion. The failure mode for a stainless bolt in a stainless plate is for the bolt to shear.

Personally, I would rather have to repair a stripped plate than figure out how to fish out and repair a galled and sheared bolt.

what about when the corrosion between the ss bolt and the al backing plate is such that you twist the head off the screw- or worse, twist the bolt off halfway along the bolt. This is what happened to one of the 6 bolts that hold the mast base plate to the deck. For whatever reason the F boats have aluminum backing plates everywhere.

Tons of penetrating lubricant, an ez-out, and a prayer.

Those plates must have been uber thick...usually the aluminum will fail before it breaks the bolt

the bolt goes through a 1/4 inch aluminum plate (part of the mast base) through about 1 inch of deck (where the bolt broke) to the backing plate which is maybe a 3/16 plate of aluminum(although I suspect slightly less). Problem is you can't get to the backing plate without cutting an access port in the plastic which is the headliner in the head. I haven't cared too much since the consensus is that the sheer amount of compression and the existing 5 bolts are enough to prevent movement.

Mine broke in the aluminum plate because of corrosion ,then the plate broke loose from the laminate.Fun Times.

whats the big deal about having an inspection port aft of the front beam and actually having a friggin nut on the bolt rather than tapping straight into the backing plate? I WISH that was SOP on my big boat. It is on the Blade, at least my hulls.

My upper adjusting eye screw is seized in the rudder casting. Any remedies on how to get that bugger to break free??

Philip: I had the same problem. Hitting the casting with a heat gun and soaking it in PB Blast helped, but the eyebolt was not reusable.

That's fine, I just don't want to break the head off trying to get it out.

I also clamped the eyebolt in a bench vice to get enough torque on it. Your mileage may vary.

Snobol is very good at removing the corrosion. The thick stuff stays where you put it. Put some on and let it sit over night, rinse and repeat. Use patience, it didn't get corroded over night and you won't clean it out overnight.

if you've laminiated in a stainless steel backing plate, would it not suffer from that anaerobic corrosion that I've seen some shroud plates erode from on leaners?

I think the type of stainless matters and whether or not it's been electro plated.

Snobol?. . . as in the toilet bowl cleaner?

Yes.