I'm in the process of finishing a Lazy Bee fuselage. I was bolting on the
engine mount after covering when one of the blind nuts popped loose. The
Bee is a real PITA when it comes to working inside the fuselage, and there's
no way I can get my hands inside. The blind nut has something inside that
makes turning the mounting bolt difficult. Any suggestions?
Thanks in advance,
Try this...stand the Bee on its nose and carefully drop medium CA 'bombs'
trying to hit the edges of the blind nut. If successful then carefully run
through the threads to clean up the obstruction.
Failing that, push the defective blind nut back and shake it out of the
Run a string through the hole and use it to fish a new one into place.
Good luck !
On 8/12/2004 10:27 AM Ted shuffled out of his cave and grunted these
great (and sometimes not so great) words of knowledge:
Replace the blind nut with a new one. If you think the blind nut has
stripped out the wood, check your local hardware store for blind nuts.
The ones they have USUALLY have a substantially larger back (head ? ) to
them so they will bite into fresh wood.
For installing the blind nut in a PITA location I do the following:
Insert a Vaseline coated bolt into the blind nut. The bend a piece of
1/32 or 1/16" wire to get to the underside (back) of the area then use a
drop of thin CA to attach it to the back of the blind nut. Remove the
Vaseline coated bolt. Use a LONG bolt with an OVERSIZE washer and
thread the bolt through the hole and into the blind nut and tighten the
bolt down to pull the blind nut into the wood. Then pop the wire off.
If you can get to the back side of the blind nut, (I use a long piece of
capillary tubing for this) reinsert the Vaseline coated bolt, then put
some thin CA on the back side of the nut to "lock" it in place. The
Vaseline prevents any CA from getting into the threads.
Hope this solves the problem.
Read more model magazines!
This has to be one of the most-repeated tips after the
What all of the tips have in common is fishing something
through the firewall from the front (wire, nyrods, cable,
weed-whacker string, etc), sliding the new blind nut on, then
attaching some big thingy behind the blind nut and hauling it back
through the fuselage to the firewall where, if your snake is
strong enough, you can pull it far enough into the old hole
to thread a bolt into it and snug it up.
If you're brave and have confidence in your snake,
you can slather epoxy on the outside of the T-nut
after protecting the threads with vaseline or some other
I'm not good with T-nuts, so I go easy on the outside
glue myself, but it does seem like a reasonable step to
take to make sure that the thing stays put when you're
done with the process.
Here's a shortcut I haven't seen or used myself, but I
think it is worth considering: cut a hole in the firewall,
centered between the mounting holes and large
enough for you to get a finger in to help set the T-nut
and get it threaded straight. Especially with a Bee,
you don't need a solid firewall to keep the engine
on the aircraft. Some big honking gasoline engines
need a hole cut behind them through the firewall
in order to clear their carbs, so the loss of some
material from the center doesn't seem to be a
If you're anxious about the hole, cover it with some
balsa or lite ply when you're done.
Some of the pattern guys use 1/8" aircraft ply for
firewalls instead of 1/4". They mount YS engines to
them, too. I haven't tried that myself, but I am convinced
that a lot of our firewalls are overbuilt for the real
needs of the airframes.
When you make a decision, let us know how it turned
If you are concerned about the firewall, consider drilling it out and
plugging it with a much larger dowel, using epoxy to glue the dowel in. Then
redrill the hole for the engine mount.
To replace the blind nut, try this. Get a piece of Sullivan (or other)
pushrod CABLE. Feed it through the engine mount hole, back through the fuse.
Place a blind nut over the cable. Put a wheel collar, behind the blind nut,
on the cable and tighten it down. Now pull the cable until the blindnut
starts into the wood. Push the cable back into the fuse. Remove the wheel
collar and the cable. Put a bolt with a large washer on the engine mount
bolt and tighten, thus seating the blind nut. Remove the bolt.
Your plane has a light firewall, so don't pull too hard on the cable. It
might take two or three attempts, but, this method takes the frustration out
of replacing blind nuts.
This has worked for me...
Push the old nut out... Push an appropriately sized of weedwhacker line
thru the firewall from the front and thread a new blind nut onto it. Wet
the flange of the nut with thick CA and pull into place... Let the CA kick
and unthread the line...
Thanks to all for your suggestions! I got a bolt in far enough to get it
pulled back flush against the firewall and then managed to dribble enough CA
around the edge to hopefully get it stuck back. Again, I really appreciate