Minor Projects

Last weekend we completed a couple of minor projects on the boat.  We had been meaning to change the impellers on the engined since last summer on the delta when Scott had problems with his raw water cooling.  What the impeller does is draw raw water from whatever body of water you are boating in, through the raw water cooling system and where it helps take heat out of the engine and then goes out the exhaust.  If the impeller is not in good condition it can lead to overheating and can even cause engine damage.  Since we didn't know when the impellers were last replaces it seemed prudent to change them out.  There was one spare on the boat so we decided to replace the impeller that was easy to get to.  The engines are nearly identical and the impeller is located on the port side.  This makes the impeller on the starboard motor handily accessible from the center of the engine room and the port motor impeller impossible to access as it is up against the fuel tank.  I have absolutely NO idea how we will get to it to change it, though after the experience of changing the "easy" one, I think we will be hiring someone to change the other one.  An impeller is a small circle with fairly stiff rubber "legs" all around it, kind of like the wheel of a mill house, if you now what I'm talking about... the impeller is a tight fit and the "legs" have to be pre-bent in the correct direction for how they will spin before it is pushed into place on a spindle that goes it the center of it.

old impeller in place

Now we all know that there is nothing simple about any boat project, but really, how hard could this be?  We just had to remove six screws that held on a brass cap, pop out the impeller, pop in the new one, put the plate back on and Bob's your uncle (whatever that means).

So the six screws in the plate.  The first three were no problem, there was easy access and I was able to use a normal screwdriver and they came out easily.  The other three... none of the above.  I could only get to them with the shortest handle screwdriver and I could not get good leverage on them to get them to unscrew.  I should have realized this was a harbinger of things to come.  I got Matt to get out the last three then he started tyring to pry out the impeller.  At this point I was in the galley polishing the brass cap we'd removed and I heard the cursing begin.  Apparently things were not going well with "popping out" the impeller.

I went back to check on Matt and he was really annoyed.  He hadn't wanted to do any boat projects and here he was with an impeller fractionally removed and me insisting we should finish what we started and change the thing so pretty much in disgust he told me to try it.  I could not get it to budge.  Of course we were trying to remove it with pliers and screwdrivers and what not and not a proper purpose built impeller remover.  This is about when we started texting all our marina neighbors to see if anyone had such a tool.  No luck. 

I was waiting for West Marine to pick up the phone when Scott came by, Matt told him our predicament and he said he had a puller.  I hung up on West Marine of course right as a person finally came on the line.  Scott had not had one of this tools when he'd changed his impeller at the Delta last summer and the tool was brand new, still attached to the package.  We were super optimistic now that we'd have the impeller out in no time.  Yeah right. 

Matt tried first and again there was much cursing emanating from the engine room.  Again I asked what was wrong and he said there was not enough clearance to get the tool in.  Again I took over to see what I could do.  By taking the tool apart I was able to at least get the "claw" part of it gripped onto the impeller but the part that is basically a giant screw that leverages against the center spindle the impeller fits on to pull the impeller out as you screw it in would not go on due to the lack of clearance.  If we could have cut about 1/2 off it we could have used it but we didn't want to modify our friend's brand new tool!  I tried threading a screwdriver through the claw but did not have the strength to pull the impeller out.  I convinced Matt, over muttered protests, to give it a try and he was able to finally "pop" the impeller out. 

Sooo... now to the easy part of putting the impeller in.  The trick here is to hold the "legs" bent the right way as you push in the impeller.  Matt decided the best way to hold them would be with zip ties.  We ended up with about 52 zip ties in the bottom of the engine room before Matt was able to get a couple on there and get the new impeller back in place.  He needed a break after that so I put on the new "gasket" that came with the impeller (a thin piece of paper?? ok well I guess the engineers know what they are doing) and then screwed the cover back on.  After that, Matt wanted to make sure it wasn't leaking so he sat in the engine room while I fired up the motor.  No drips.  Yeah.  But no way we want to try that on the inaccessible one!

zinc

The other thing we did was find the zincs in the cooling system.  The zincs help prevent corrosion in the cooling system because zinc will corrode before the metal of the system will.  The zincs need to be checked to make sure there is zinc left protected your system.  We had no idea where they were or what they looked like.  Friends told us to look for somewhat large brass hex bolts, which have the zinc attached to them on the inside.  Well, is it hard to spot anything brass because the motors are painted a uniform beautiful blue. We found a couple of likely candidates and had a friend confirm which were zincs.  We then removed one and found we have plenty of zinc left.  We do need to buy replacements to have on hand but we aren't in dire need to switch them out!  Some good news for the day...