Robin: I plan on retro-fitting wing tanks in the the project I took over with 5" OD x 0.052 wall irrigation tube as you describe but have found the max length to be something a little over 5'-0" because of the spars taperas you move to the tip. It appears that such a tank would have a capacity of 4.9 to 5 gallons by my calc using 231 cu. in per gallon. I bought (4) 5 ft. pieces for the job thinking I could put (2) side by side in each wing and interconnected at the ends but alas I thing the aft one must not exceed 4-1/2 inch OD because of the reduction in wing thickness as you move back so check carefully. The 5 in. tube weighs between 0.9 and 0.95 Lb per foot and I paid $98 for (4) 5ft pieces + freight. The total freight was $16 for UPS charges from the "Hastings Pipe" plant in Hastings NE about 600 miles from where I live. All total the single package weighed a little over 20# say 10 kilos.
I spoke to a lady named Martha(I think) at the '06 gathering that used 4 in plastic pipe to retrofit tanks into her wings without opening the entire wing. I think anchoring it as you describe makes sense. I think she cut course teeth in the end of a pipe and used that to cut thru the foam ribs which should work. Guiding the operation may pose a probler but perhaps with the leading edge in a cradle the spar & the upper wing skin would provide an adequate guide and you would only need small openings to do the fuel fill and tank anchors in the wing. You could also consider locking the tank with injec foam in the (1) of the cells created by the wing, tank ant (2) of the foam ribs. The WAF end should be easy as it is accessible. Perhabs if Martha or the person that I talked to @ the last gathering could weigh in on this and be of help. Don Lively Burlington IA -------------------------------------------------------------------------------- ----- Original Message ----- From: "Robin Macdonald" <r.macdon...@clear.net.nz> To: "KRnet" <kr...@mylist.net> Sent: Saturday, May 26, 2007 8:28 PM Subject: KR> Rebuilding Wings. > Netheads. > > I have acquired a KR2, & I would like to rebuild the outer wings. The wings > are heavy (approx 50 lbs), the aileron hinges are about 1/4" concave, & I > would like to put tanks in the wings. > > Unfortunately I will stick with the RAF 48 airfoil I don't want to do the > inner wings & reposition the rear spar. > > My method fasten the WAF's to a block of wood, Ali channel or what ever then > cut the tip off & stick a block of wood to the outer end of the wing (not > sure how, screw, glue or what ever). Then stick a piece of tube in the blocks > of wood & use them like a rotisserie. > > The block of wood at the inner end would be to keep the WAF's & spars in the > same relative position. > > Then take the lower skin & nose off & rebuild, probably use Mark L's method. > Then turn over remove the top skin. Fit tanks probably 5" irrigation tube X 2 > ( length depends on how much fuel I want). > > One thing I was think about with fitting irrigation tube. Depending on the > length what is the expansion/contraction going to be compared with the > wood/fibreglass structure. I thought of gluing the outer end (where the > filler would be) in a cradle or what ever & allow the rest of the tube to > expand/contract > > Then do top skin etc. > > My questions are > > Has anyone done anything like this before. Any thoughts, suggestions etc. > > Thanks > > Much appreciated. > > Robin. > > New Zealand > > r.macdon...@clear.net.nz > > > _______________________________________ > Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp > to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net > Post photos, introductions, and For Sale items to > http://www.kr2forum.com/phpBB2/index.php > please see other KRnet info at http://www.krnet.org/info.html >
