What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Help with wheel pants

D

Dorfie

Well Known Member
On the main (U-1057A) and nose (U-1013A) wheel front halves of the wheel pants there is a fine ridge near the mating surface with the rear part of fairing. It extends all around the rear area and also where it will fit over the wheels. The plans does not mention this nor advise to trim to this line. It will remove about 1/8 to 3/16 of inch off. The line is very distinct and one can feel the ridge. It also appears to be pretty straight. Can anyone recall this? Must I trim to the line? It seems that should I leave the ridge it will have to be sanded down eventually for painting.
Thanks.
Johan
 
I am working on my 7A pants now, in those plans they say to sand down on the front half, a place where the two lay ups make that area thicker. These things need hours of sanding and prep work to make them match up and fit correctly. Many many hours of sanding filling and block sanding......did I mention they need to be sanded:D
 
If it is anything like the pants on the RV-9A, trim to the line, then sand it as needed to match up to the other half. The lines are there for trimming. The lines where the tire opening is need to be opened up quite a bit more in order to fit around the tire. I started with a 1/2" more and still needed to trim to get to the 5/8-3/4" space as specified by Van's.
 
What Bruce and Brett mentioned is spot on. To make your pants look good, you are going to spend some time sanding and filling multiple times. I don't recall if it was DanH or somebody else, but there is an excellent thread in the VAF archives about finishing your wheel pants.

What you are concern with now is the easy part. Getting the joint seam parallel with an even gap is a little more difficult. And not mentioned in the plans either. At this point in the build you'll find that the instructions are pretty terse.

Basically sand the two halves to the best of your ability to get them correct. At least on my pants, I also had a problem on the one side where the corner where the flange is, was full of craters making a very ugly and clearly not a ninety degree corner.

You can resolve all these issues by placing clear packing tape on the female half. Make sure you've got the edge and about an inch back covered on the top and bottom. You may want to out a couple layers of tape to allow for paint thickness later. You don't want to accidentally epoxy the two halves together. Then fill in all the voids with micro. This will give you a perfect seam.
 
I'd suggest caution regarding "trim lines". The kind of line you describe was probably located by inserting a fitted/finished wheel pant part into the finished or almost finished mold, then scribing along the edge, into the mold surface. The scribe line location is as precise as that particular wheel pant.

A rough guide? Sure. Creep up on it...do your own fitting. Cutting directly to a scribe line is probably the #1 cause of requests for "How do I extend an edge?" ;)

Here's the quick way to straighten the seam on the rear half.

http://www.vansairforce.com/community/showthread.php?t=16999
 
Thanks guys for all the suggestions. Where were you guys yesterday morning when I spent 4 hours trying to get the two half's lined up, Just kidding:). All seriousness aside this is what this site is all about. I really do appreciate the help and suggestions that all of those that have gone before and the willingness of their help. A big Thank You.
Scott
 
Great info and link

Thanks for all the replies. I've done as DanH suggested in the linked thread. Have two more questions/issues.
1. I glued good quality sanding paper to large flat surface that I used to sand the aft ends of the front section. It is very prone to "chatter", and rotating the wheel pant on the sand paper helps. Problem is that the slightest pressure on the wheel pant front halve tends to open up the gap where the wheel will go. This resulted in taking away more material at those free ends. When put on flat surface, the ends are somewhat off the surface. It looks like nice straight line, so in the end I think when filling the joint it will look OK.
2. How do you get the unevenness (height difference) between the front and rear halves filled? It seems you will have to fill OVER the gap, which in effect will fuse them to some degree. I have the same problem picturing how to do this on the cabin doors. I know how to get the gap looking good. Not sure how the get them to same profile without filling across the gap.
Thanks.
Johan
 
Dorfie said:
I have the same problem picturing how to do this on the cabin doors. I know how to get the gap looking good. Not sure how the get them to same profile without filling across the gap.
Thanks.
Johan
Click to expand...

LOTS AND LOTS of filling, rubbing down, filling, rubbing down........... :mad:
 
Dorfie said:
2. How do you get the unevenness (height difference) between the front and rear halves filled? It seems you will have to fill OVER the gap, which in effect will fuse them to some degree. I have the same problem picturing how to do this on the cabin doors. I know how to get the gap looking good. Not sure how the get them to same profile without filling across the gap.
Thanks.
Johan
Click to expand...

With regards to the doors, I did the following;

1. I did not follow Van's instruction re fitting a 45* edge on the doors to the rounded corner of the cabin top. The edge on my green top was so inconsistent that it was impossible to fit the door edge to it. The steps below left me with a squared off door edge and a squared off cabin opening edge. Looks good and has held up well over almost 4 years.

2. Trim the doors to fit the cabin opening; install the door hinges, door pins & guides, as well as any secondary latches, and adjust them to their final positions.

3. Trim & sand the door edge so it is 90* to the outer face of the door. Apply 3 layers of duct tape to the door edge, around the entire door. It will be perpendicular to the outer door face. With a razor blade, trim the duct tape, using the outer face of the door as your guide. The edge of the duct tape will be flush with the door face. Some of the duct tape will extend towards the inside of the door. The thickness of the duct tape will determine the final gap between door and cabin top. Take a little time to apply it so you have the same thickness all the way around the door; no wrinkles, no gaps. Three layers of tape left me with a final gap of about 1/16th inch, once primed and painted. Add more layers of tape if you want a bigger gap.

4. Close one door, making sure the duct tape doesn't pull away from the door edge. Fully latch the door. With a squeegee or similar tool apply micro to fill any low spots. In my case, the door was higher than the cabin edge all the way around. Filling the low spots on the cabin side also turned the original inconsistent round edge into a nice smooth squared edge.

5. After the micro has thoroughly cured, open the door from the inside. It will probably take some gentle pushing. You may have some minor breakout of the edges on either side of the tape. Pull the tape off and admire your fitted doors.

Jim Berry
Rv-10
 
Dorfie said:
2. How do you get the unevenness (height difference) between the front and rear halves filled? It seems you will have to fill OVER the gap, which in effect will fuse them to some degree.
Click to expand...

First scuff the inside of the front pant and the outside of the flange on the rear half to remove any lumps or other anomalies. Then locate and pilot drill 1/8" at all screw locations. Now clecos will hold the parts together firmly so you can judge/measure any height mismatch.

If the front half is taller, sand down the flange on the rear half using 80 grit on a flat stick.

If the the rear half is taller, add small (1"x1") glass cloth shim pads to the underside of the front half at each screw location. Just stack up as many wet plies as necessary at each location. Err on the fat side; you can easily sand the stack thinner if it is too tall.
 
Jim, Dan and Mike

Thank you much. I am now a better informed builder and actually looking forward doing it! Great advice.

Dan, do you not use any filler on front and rear halves to get the hight even? It seems you get it all done by sanding down high spots on front and spacing the low spots on the front half. I keep coming back to this since it is the doors that will need the same process. I'll be trying your method hopefully tonight. Also, should I wait with this part (getting the gap even and hights level) untill the pants are mounted on the plane?

Jim, I have already sanded the 45 degree on the doors and frames. They fit pretty well, but not as good as the process you described. I will probably sand the door 45 degrees down some, then use your method to get an even gap and even out the hights across the gap.

Mike, I have been eyeing your installation method and has it all saved and planning to use when the time comes.

Thanks to all.

Johan
 
Dorfie said:
Dan, do you not use any filler on front and rear halves to get the height even? It seems you get it all done by sanding down high spots on front and spacing the low spots on the front half....Also, should I wait with this part (getting the gap even and hights level) untill the pants are mounted on the plane?
Click to expand...

Maybe a spot of micro here and there, but not much. I recall mine as mostly in need of shimming with glass patches to raise the front half. Do what works.

No, don't wait. Turn the two halves into one slick body, then mount.
 
You must log in or register to reply here.
Back
Top