Bruce - it all depends upon your budget and what you want to spend for the auxiliary fuel cell on the 1800. Over the years there have been several styles that have been made for our model of Wing and of course some individuals have improvised with either custom built tanks or used a pre-made auxiliary fuel cell and adapted that to the bike.
Ron Smith was one of the original designers of a Goldwing fuel cell and although he regretably passed away his tank design can still be purchased through the Sampson site and his partner who still makes them. You can also contact Quickdraw through this site and get information on his tank design and find out about the availability and cost (I have that tank and have used mine for about 1 1/2 years with a great amount of satisfaction). One adantage of our fuel cell over Ron's design is the ability to fully open the rear trunk, whereas with the Sampson tank you can only open the trunk partially.
Another option could be to use a Summiit Racing 4 gallon aluminum fuel cell (RCI equivalent) and add a safe way to mount it to the rear seat along with the necessary adaptors, valves and lines. I explored that option early on (along with a custom built tank), but the opportunity came up to get one of the last tanks of the first batch of tanks from Quickdraw so I jumped on it. I still think the Summit 4 gallon tank would make a great fuel cell for the 1800 if you could have a mounting mechanizm made that would work to both hold it and remove it easily when you wanted (you also need two quick disconnects (Sampson's work best) for the fuel line and vent line).
A good well designed auxiliary fuel cell is a great thing to have if you do a lot of traveling and put a lot of miles on your Wing.
Good Luck,
DaleC
Thank you Dale for your infomation. I have/had Quickdraw's website listed as a 'favorite' and tried to access it last night without success. Can you put me in touch with him? IIRC, his tank was somewhere near $1000 and Sampson is ~$600 or so. I like the appearance and design features of your tank; just not sure I can justify the additional expense for something that I would use very little. I've planned a significant IBA ride this coming September and an auxiliary tank would almost be mandantory for a successful ride and finish. Thank you again for sharing your knowlegdge and pictures with me, I appreciate it!
P.S. Some have used the plastic Jasco tank on a variety of motorcycles, but I'm not that impressed with the construction quality in the event of an accident. That's just my own opinion and preference.