Plonk Posted October 28, 2020 Report Share Posted October 28, 2020 I have obtained a 2.5 ltr polished aluminium tank to use as an header/expansion tank near to my back-boiler (at the front of the boat) and another (1 ltr) with a sight window for easy checking and expansion at the other end of the boat (connected to the highest point in the pipework). They will be connected into the system with 2 or 3 ft of PEX tubing. As there are lots of copper pipes throughout, are the alloy tanks (or any other bits) likely to corrode? If I understand correctly they will not be making a circuit and as the voltages would minimal if this is wrong, I am hoping the antifreeze/water mix will not be a good enough electrolyte to pass through the plastic pipework to the copper. Any advice gratefully received please. Plonk Link to comment Share on other sites More sharing options...
Tracy D'arth Posted October 28, 2020 Report Share Posted October 28, 2020 I think you worry unduly about corrosion, most engines contain mixed metals. Link to comment Share on other sites More sharing options...
dor Posted October 28, 2020 Report Share Posted October 28, 2020 Aldi specified a SS calorifer and Hep2O pipe rather than copper for use with its 30xx boilers due to the aluminium internals. Not sure how significant it is. They did say it's not a problem having brass fittings with Plastic pipe. Does the antifreeze/anti corrosion additive make the water more conductive? Link to comment Share on other sites More sharing options...
blackrose Posted October 28, 2020 Report Share Posted October 28, 2020 (edited) Galvanic corrosion of dissimilar metals immersed in an electrolyte can only occur if those dissimilar metals are electrically connected and if the electrolyte is condusive to corrosion. So, connect your header tanks to the copper pipes of the heating system with plastic pipe or flexible rubber car heater hose and fill the system with antifreeze or inhibitor with anti-corrosive additive and you'll be fine. This stuff is pretty good. Edited October 28, 2020 by blackrose Link to comment Share on other sites More sharing options...
Plonk Posted October 31, 2020 Author Report Share Posted October 31, 2020 Thanks folks. I will fit them. Happily reassured! I remember now that there is copper tubing in the engine cooling system connected with rubber hose. The head and exhaust water jacket are aluminium and the boat is 21 years old and counting with no problem so far.... Link to comment Share on other sites More sharing options...
Featured Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now