** This thread discusses the content article: Gas Bag Setups **

Hi, I have just read the article on gas bags and hope someone can help me with a couple of queries. I am building an off shore boat and want to use 2 No. gas bags as fuel tanks. I am unsure whether to locate the outlet of the bag forward or aft. If arranged aft is there a possibility of the fuel from the forward tank draining into the aft tank due to forward motion?. I was considering placing both tank outlets forwards thus preventing the draining problem. Anyone got any ideas please.

I put my outlets towards the back because the weight of the fuel will force it that direction while underway. I've seen them mounted in all sorts of directions though. Never seen two bags hooked together if that's what you are trying to do. Would have to come up with a way to fill and purge air from both bags.

GAS BAG. That sounds like my ex-wife.

Steve by ex does that mean you were running two gas bags?

Mercury, I once went to a tackle store and my ex stayed in the truck while I went in. When the cashier rang up my purchase, she asked me if I wanted a bag. I told her "no thanks, I have one in the truck".

Hi Guys
As my new boat will be using a Gas Bag I found the article very helpful. In respect of two bags I would think that provided that all air is removed during the filling process, there should be no issue with connecting two together as in essence the system comprises of one sealed system. Others with experience of using two bags will correct me if wrong. However I guess it might depend upon how you plumb the two together. I would imagine that with two bags you’d have the fuel feed to the carb coming from only one of the bags, the second one there to feed the primary bag as it drains.

However for me being totally new to Gas Bags (excluding the context of spouses!) I will be sticking to just the one bag to start with for my new boat. As it has a 2 litre capacity it should more than suit my requirements.

An interesting point in the article was that solid vented tanks smell when one’s boat is stored. Simple solution to that is to block off the vent in storage.

Also, in respect of having the bag sat under the engine, that for me would be concerning even though I’ve no doubt that success stories are abundant using this method. My concerns would include:

1 Ability to visibly inspect the bag and access to it.

2 Potential sharp edges from engine components/fittings contacting the bag.

3 Heat from the engine casing.

4 Damage to the bag should any of the engine components/mountings come loose.

These are only my thoughts bearing in mind that the concept of this fuel system is new territory for me. Further advice and comments will be welcome.

Cheers
Craig

Thanks for all the feed back including spouses. Seems I am trying something new, but if I hang 2 half filled bags one above the other and both having there outlets facing down, then the top bag will drain into the bottom one. This is what I was afrain of as it will affect the balance of the boat. I will probably try it out and see what happens. Thanks to everyone for their comments, they are appreciated.

I was thinking about using 3 small 250ml bags laying side by side across the bottom of the hull on either side of the runners.
The 250ml bags have dual outputs of which one on each bag could be conected to the others in such a manner so as all three will auto level balance.
The other connection I want to connect to a three way splitter and then to the MHZ scale threw the hull gas port filler as this would spee filing and because the filler shuts off fuel to the engine as you fill thus reducing need for another valve, and all but doing away with most of the air in the system after the initial fill or after filling post storage for season or what not.