Two engine room leaks for the price of one! Is this as bad as I'm afraid it is?

[Sailing Amok]

I was able to get the hx off the boat this weekend, and will bring it into a radiator shop to be pressure tested this week. Would folks suggest cleaning it up on my own (external and internal) and then bringing it in, or having it pressure tested as is so I know if there was leak at baseline? I haven't opened it up yet, as I don't have gaskets at this point anyway. From photos, it looks like the end cap gaskets could just be cut out of a sheet of gasket material, or is it best to purchase them. I mean it's just a disc. Speaking of gasket material, the cork or whatever it was that was between the hx and the engine is completely rotten, any suggestions regarding what to replace that with?

While I'm doing all this work on the cooling system, are there any other projects I should tackle at the same time?

Ken, thanks for all the info!
I'll look into the new clamps, I take it they wrap around the hx like a worm clamp? I've seen photos of some like that.
With regards to shipping, if it changes anything, I have a place just across the border that I ship to regularly. Given Thunder Bay's location, it's often easier to get things shipped to Minnesota rather than from Canadian sources. We don't even have a local chandlery here, or I'd gladly support them.
The T-stat to manifold hose looks to be in good condition, so I suppose I could leave it as is, or order one, and if the wrong one arrives, it's not the end of the world.

[KWKloeber]

@Aaron

Seakamp sells the gaskets if you are ordering the brackets but they are nothing magical.  I think they are neoprene but that red gasket material from an auto parts works just dandy as well.

The brackets don't encircle the Hx - they are more like a half circle -- some folks call them "spoons."  The Hx is clamped to the spoons w/ worm drive (USE AWAB or ABA clamps, NOT slotted clamps) or T-bolt clamps (overkill) that Seakamp also sells for its Hxs.

While you're in there you might run a green 14 ga bonding wire from the Hx cap bolt to a good engine ground to bond for galvanic corrosion (a Seakamp recommendation.)  The bolt uses a 3/8" ring terminal.

[Ron Hill]

Aaron : In case you have a cracked end cap, go on line and look for a Sem-Dure End Cap assembly (Kit #5373) for a 3" SD  HX.  It has the gasket, end cap, "O" ring and bolt.

Be careful tightening that endcap bolts because you can collapse the end cap!   So Easy does it! 

A few thoughts 

[Sailing Amok]

Thanks guys, I'm going to order the parts tomorrow. The bonding strap sounds like a good idea, though our pencil anode barely erodes at all over a season, so I don't think galvanic corrosion is too much of an issue here.
I managed to improvise a pressure tester, and the hx seems to be ok. I'm actually a little disappointed, as that would have been a relatively easy explanation for the missing coolant. I guess it will remain  a mystery until I can run the engine and do more testing. I'll open it up this weekend  and start the cleaning process, repainting etc as per Main Sail's instructions on his site. Hopefully I can get all the parts fairly quickly and get the cooling system back together for launch on May 14th.

[Sailing Amok]

All my hoses have finally arrived, so time to try putting this thing back together. I purchased some cork gasket material to put between the hx and the bell housing. It looks like what was originally there was a synthetic black rubber of some kind, but I figure cork should do the job. Any suggestions regarding what to tack it to the bell housing with? I was thinking a couple dots of RVT. The original material seemed to have been stuck on pretty well. Also, the new Seakamp brackets came with little squares of gasket material for between the bracket and the hx. Should I also put something between the worm drive and the hx? Perhaps some inner tube? I've read that it may be better no to isolate the hx from the engine, from a corrosion perspective.