The wing in my hog bipe doesn't quit fit right in the saddle, { rocks } I have corrected this in the past by sanding the saddle but I was wondering on the bipe if I should because of the top wing Mounts
Should I

A. continue to sand for a good fit. or
B. glue dowels and drill wing and bolt then when lined up " build up" wing saddle in low spots with epoxy and micro balloons.

That would depend on the wing incidence. You will either have to sand or build up depending on how it sits.

If its been flying and flys good, then I would use some epoxy with micro balloon as a filler. Incedence is critical in the wing saddle. That has to be right first and foremost.
Edwin

I assume you are still building and not finished the kit yet. First thing to do is get all the incidences correct. Check both wings and the tail group. Then mount both wings. AFTER the bottom wing is mounted and you are satisfied with the incidence go back and fill the gaps with micro balloons and epoxy. It is not hard to do and will make a perfect seal.

1. Iron on two strips of monokote on the bottom wing where it contacts the saddle. It must be about 1" wider on each side of the fuselage.

2. Mix up a batch of micro balloons/epoxy and dab it on the wing saddle all the way from front to back and on each side.

3. Bolt the wing to the fuse and tighten.

4. Clean off the excess that oozes out with a putty knife then let dry.

5. Once cured take out the wing bolts and tap on the wing until it pops off. It won't be all that easy. Be patient, it will pop off after you tap for a little while.

6. Remove the monokote and sand the fuse sides smooth.

The joint should now be perfect. I always do this prior to covering.

Carlgrover is onto it here. AND if you use a little "veinerslidder" (Vasaline) on the moneykoat before you put the epoxy/micoballons on, it will pop right off with no trouble. I've also just used packing tape on the wing instead of covering material with a coating of "veinerslidder" works just the same way. Ends up with a perfect joint.

I will try that. I have never worked with micro balloons before. I have always just sanded to set the wing in the saddle for good fit and proper incidence.
I was a little worried sanding the bipe wing saddle because the top wing attachments are dependent on the bottom wing set.

I haven't built the Hog Bipe but most biplane designs are more concerned with the angle of the the wings and stabilizer relative to one another, not the physical distance. A spacing of wings +/- 1mm is probably insignificant.

Also, most designs establish a reference line on the fuselage that each wing and stabilizer angle is measured to independently. In doing it this way, one avoids a chain of insignificant errors compounding into a noticeable trim problem - sometimes called tolerance stack-up.

The hog bipe is pretty much built with a " Tab and Slot " construction method. Most of the mounting holes are already pre-drilled for you. The cabin struts and the wing to wing struts are pre- drilled as well as the ply plates they bolt into. It is my understanding that most people who built this plane said if you built it right it is almost fail safe as far as the wing incidence goes just need to line up perpendicular to the center line. And that's pretty much how my build went. But I do have a Little gap on the back of the saddle on the left side and in the front on the right side. Wing kinda rocks a little. I already mounted the dowels and drilled for the bolts. Now the wing lines up. If I crank down the bolts really tight it will pull the wing down into the saddle. Just kidding. I will now mix up some micro balloons epoxy and fill the gaps using saran and a little petro jelly.