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Cooling Duct Scribe Lines

N223JH

Well Known Member
Well I'm back with yet another scribe line question. This time it's the multiple scribe lines on the cooling duct. Cut to first is clearly not enough. Can somebody who's been there give me the word? I'd hate to try and lay up a patch on this puppy if I overcut. TIA Jim

RV12 #120264 FWF
RV6A sold yesterday!
 
I don't remember any multiple scribe lines. Which side? Picture? If I know where you encountered this I will look at mine, which I have trimmed but not yet installed.
 
Lines

John, There are at least 3 sets of lines around most sides of my duct. I suspect the outermost, which I cut to, is inadequate. And the lower cowl doesn't want to close up on the hinges with the duct up against the radiator on the firewall.

If you could get a ruler in there and make a few measurements in different places, I could probably extrapolate from that. TIA Jim
 
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Jim,

I did not have all those scribe lines. I had one set that was pretty clear (as scribe lines go). The only other marks that could be interpreted as scribe lines were some ridges in places, which seemed more like marks in the mold, but not scribe lines. I looked at the strips that I cut off when cutting to the scribe lines. Most were in the 1/8 to 1/4 inch range, some a little more.

I don't know exactly where to measure for you. Keep in mind, I haven't yet done the final fitting and fiberglassing. I am not able to work much on the kit for the next week or so, therefore I won't get back to the fitting for a while.

John
 
John, Appreciate the help. If you can get some measurements, great. I will evaluate based on your cuts. The inner scribe lines I have are just high enough to catch a Sharpie so it's tough to tell whether they are "the ones." Jim
 
Fiddly job

Hi Jim,
I did this section a few weeks ago , and found it very fiddly. First off, I would be sure the Radiator with its face plate are in their final position, with clearance for the heater door to fully open and at least specified clearance between the fins of the radiator and the cooler box ribs.
I would cut the cooling duct to the first scribe line, expecting to trim it more later. Drill and cleco the duct in place; the fit around the oval air intake determines where the radiator end of the cooling duct will be. Now see how much space you have between the face of the radiator and the trimmed end of the cooling duct. There needs to be a big enough gap to give the cowl duct interface ? inch clearance off the face of the radiator. The gap is for the rubber duct seal.
I found I had to cut the cooling duct back a lot more than the 5/16? specified in Step 8 on page 49-13. More like ? inch. This is because the plans don?t allow for the thick fillet in the angle of the cowl duct Interface.
Its fiddly as I said, but the dimensions are not critical. There is plenty of overlap between the cooling duct and the duct interface for bonding. Over-trimming 1/8? will not be a problem.
Just don?t do what I did ? let the duct interface move out of position when you bond the duct interface to the cooling duct. You might be up for $27.70 to replace that itty bit of rubber cowl duct seal B!
Best of luck, Rod
 
Rod, 'preciate the guidance. I suspected that fit wasn't overly critical but after having the canopy and cowl on and off about 50 times, I was looking for some mercy from Van's plans-writers on the homestretch of the fibreglas-fitting. I'll try and enjoy this while I fret about the painting-to-come. Jim
 
I see in the pictures you painted the inside of the duct black. How does it look? What type of paint did you use? How did you prep the fiberglass?
 
Painting the Cooling Duct

Please explain the reason for painting the inside of the cooling duct. Once it's afixed to the cowl you can't see it. It also adds more weight.

Art Pennanen
 
Door seal price reduction

In a previous post I warned that if you needed to remake the interface between the Cooling duct and the Radiator, be prepared to pay $27.70 for the 42 inches of door seal rubber you will need.

Good news! When I pointed out the exraordinary price of the rubber, Pam consulted the powers that be in the Web Store for me, and they promptly dropped the price to a very reasonable $10.50.

Its nice to deal with a company that responds quickly to your issues. Thanks for your service, Pam

Rod
 
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