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View Full Version : Diesel fuel manifold materiel?



capperbar
03-16-2005, 02:34 AM
I've been asked to make a fuel manifold for an old Schooner. The engineer wants a block of brass drilled out to replace a mess of leaky fittings. My understanding is it can't be aluminum per CG reg's and needs to be documentable on the brass materiel. So specifically what type of brass or bronze should I order from Alaska Copper. The next problem is the main gallery is 1/4" and 7" long per the print I was given. Any suggestions/worry on drilling a nice staight 7" deep hole. May need to get it redesigned.
Thanks
Sav

captainkirk
03-16-2005, 03:25 AM
A good choice might be C46400 or C48200 refered to as "Naval Brass"(do a Google search for specific information).
As for the drilling of the 7" deep hole of that diameter first get a tolerence for how off center is within there specifications likely it isn't going to be to tight given the application but you might wish to clarify that with the design person prior to fabrication, you might try the old method of drilling a little ways and then turning the part 180 degrees and drilling the same distance this tends to even out the walking off center from things I have read. Personally I would use a new drill bit and give it a try on a piece of scrap prior to drilling the purchased piece of brass to see if the results meet the print specifications.

hammerhead74000
03-16-2005, 04:27 AM
Hmm... if the tolerances are tight, drill it undersize, and bore it out with a micro boring bar? Otherwise, you might have to go to a gundrilling process.

precisionworks
03-16-2005, 11:06 AM
Parabolic drill bits can usually drill deep holes up to 15 diameters. .250 x 15 = 3.75", so drilling from each end (as CaptKirk suggested) should be doable.

Here's a page from the MSC catalog that lists these:

http://www1.mscdirect.com/CGI/NNPDFF?PMPAGE=80