General building Q, how to fill a low spot
 

I need some advise on how to fill a low spot on my fuse.

I have a b25 fuse that is sheeted but not yet fiberglassed. (I bought the kit partially built) I noticed a low spot/area neart the tail, it is on the side to bottom curve. How should I fill this void?

1. use wood filler? (seems like it would be difficult to get it to stick in such a wide area)
2. epoxy/resin and micro baloons?
3. Glue some balsa and re-sand to shape?
4. Bondo?
5. Fix it after fiberglassing?

Thank you for the help in advance.

Mike

RE: General building Q, how to fill a low spot
 

It really depends on how deep and how wide the depression is. If it's large, I would sheet it in using a sandable glue and reshape it to blend, fill any small divots with a microlite filler, then glass and if you have any small imperfections left deal with them then.

RE: General building Q, how to fill a low spot
 

Thank you Tom,
the depression is at its deepest just less than an 1/8th'' deep and 1''x 7'' wide and long (although some what oval in shape).

I will run your advise.

Mike,

RE: General building Q, how to fill a low spot
 

In this situation I would use a 1:4 epoxy/microballoons mix, or some sandable balsa filler. I have heard mixing spackle with elmers wood glue (5:1) makes a good balsa filler if you don't have any. If it is a larger depression, you could glue balsa, sand, then fill in the rest with a filler.
The goal is to get it pretty good in the bare wood stage. You can use Bondo glazing and spot putty to fill in any remaining imperfections after you've glassed it.
-ron

RE: General building Q, how to fill a low spot
 

Go to your local hardware store and get a tub of vinyl spackling. Put a big blob of it in your low spot so that it is higher than the rest of the surface. Take a straight and ridged ruler (or any object like it, large spatula) press down the filling and work it to match the other surface. This stuff is extremely light, it sands and feathers just great, paints and so on. Oh, it's tough also! By the way, for the money, you get 20 times what you get in those "other" fillers and epoxies, balloons, that you might get at some "other" store, if you get my drift! You can also use the regular spackling for dry walls. I use them both. Now, if your area is extremely large (doesn't sound like it), then layer with sheets or blocks of balsa, sandable glue, and just sand to match. Then use the above mentioned for filler. It works as well as the light weight Bondo, is lighter, and it's not as hard to sand as epoxies or resins. You can also use this stuff for all around filling (cracks, holes), as well as for making filets and farings! Have fun and make it a nice one!

RE: General building Q, how to fill a low spot
 

Light weight ceiling spackle. Red Devil ? I am sold on the stuff.

RE: General building Q, how to fill a low spot
 

yup used the light wight stuff on my last plane it worked great much cheaper than the hobby stuff
Danny

RE: General building Q, how to fill a low spot
 

I second the motion to use vinyl spackling, its cheap, it sands well, and it doesn't weigh a ton.

RE: General building Q, how to fill a low spot
 

Is the Vinyl Spackle my best bet for a Fiberglass weave filler too?

thank you for the help guys.

by the way, I had to use a combo punch here. Started with some balsa and now switching to the filler to finish.

Seems to be working great.

Love the sandable glue from Pica!

RE: General building Q, how to fill a low spot
 

I use the same stuff that the body shops use not bondo but the red putty fille. It's pretty cheap if you go to a Body Shop Supply Store. You can get it in a can or tube. Cans hold more and last longer. Its very easy to smooth to match the rest of the fuse around it. I've not found any other filler that sands as easy as this stuff!!! It's called finishing putty, but if you just say the red stuff, they will know what you mean! GOOD LUCK!

Gibbs

RE: General building Q, how to fill a low spot
 

since we are on the topic,

Other than weight, what is the main difference in Vinyl spackle vs. the light weight spackle?

When should one use the vinyl vs. the light weight?

I have used both but with out cause... :) ie... what was available at the time.

RE: General building Q, how to fill a low spot
 

Can you use the lightweight spackle before applying Monokote? Is it compatible? Thx-

RE: General building Q, how to fill a low spot
 

You can monokote over lightweight spackle if you give it a couple of good coats of nitrate dope first.

Bill, AMA 4720
WACO Brotherhood #1

RE: General building Q, how to fill a low spot
 

So it has to be pre-treated for the Monokote to adhere?

RE: General building Q, how to fill a low spot
 

Any bondo type filler is going to be HEAVY.

The light weight spackles are good but have a weakness. Over large areas like yours, they're going to present a very weak surface. If you figure to solve that by fiberglassing over them, you wind up with a better result. But it's often best to fill at least some parts of large areas with balsa and then fill around them with the light weight.

They don't give iron-on much support by themselves. Day to day handling will show up as wrinkles.

CA can actually turn their weak surfaces into decently strong surfaces. It's good to make sure the CA penetrates completely into the subsurface however. And the CA adds as little weight as the spackle did. win win