ORIGINAL: splais
Dalita, You do not need to notch the bulkhead. I have a Dubro 24oz tank mounted above the wing tube. It does touch the bulkhead, but I put foam under the tank in front of and behind the bulkhead. Have not had the slightest problem. There is a picture back in the middle of this thread someplace.
PS: the tank mount is from my 102" Yak, but did it exactly the same on the 85"er.
PS2: I mounted a Slimeline smoke system in my 85 last night. got the smoke pump in front of the fuel tank and behind the battery. The 16oz smoke tank is mounted behind and below the fuel tank. Will have some pics up later tonight. It's a pretty clean install and makes the allup weight of my plane about 16 pounds. Still totally good for 3D.
24oz is Wayyyyyy too much capacity for this plane... I fly for a good 15 minutes on a 16 oz tank. Why carry the extra weight...although one could only fill 2/3 way.
The stock tank works beautifully,and is just about the right capacity. Notching the bulkhead takes all of about 30 seconds, and a small piece of 3/16" square hardwood stock makes for an excellent doubler... weighing this plane down will kill its performance.. I have seen it fly at 17 pounds and 15 pounds... NO comparison between the two. Lighter is definitely better.
Mine is on track for 15 pounds 4 oz dry... we shall see at weigh in.
DP