Greg,

Re-bedding the portholes does not usually require removal of the entire port.  Just remove the screws, nuts and the outer trim ring.  Clean the old bedding off the outer trim ring and the outer cabinside. Then apply new bedding around the outside edge of the portlight where it projects thru the cabinside and on the back of the outer trim ring.  Reinstall the trim ring and the bolts and tighten.  You are done...after you clean up the excess bedding that will squash out ....  If you're like me you will also have bedding material all over yourself, but hey that's what rags and solvent are for!!!

A couple helpful notes;  

Mark the trim rings so you can get them back on in the same orientation, as the holes (on round portlights) do vary slightly in spacing.  (With your rectangular ports this is likely not an issue.) 

Make sure to put a small amount of bedding under the head of every screw before you put them back in.  This prevents water from getting under the head and running down the threads. 

This is an easy and satisfying job that is simple.  The most difficult part may be getting the old outer trim rings off, a thin flexable putty knife works well.

Kevin 

Greg,

I'm a big advocate of 5200 for many things but NOT for bedding things (like ports and deck hardware) that may one day have to be removed.

I have always used a Polysulfide for bedding as it remains flexible and is not an adhesive.  There are a number of newer products on the market that are suppose to be better than Polysulfide.  I think 3M has something called 4000 or 4200 that is suppose to be a good bedding material. 

I have seen increased use of butyl tape sealant by production boat builders and a lot of leaks/failures related to it. If it is applied carefully with no gaps or overlaps it seems to work fine.  It does not seem seal very well around screws that are passed thru it.

I have removed and replaced the interior cabin side liner on a couple of Westsail 28's.  In one boat it was glued in with what appeared to be epoxy or fiberglass resin, on the other it was glued in with some kind of adhesive (maybe 5200). 

One alternative to removal might be to fill the damaged/delaminated area and go with painted cabin side liner around the upper cabin. 

Kevin 

Greg,

If you are bedding above the waterline, then use 4000UV because it is UV stable.  I re-bedded my portlight flange plate with this stuff.

It is more expensive than 4200, but you can get it in a hardware store cheaper than your local Westmarine.

Also, I had a much more elaborate response but the website keeps dropping my posts and I loose my messages (of course I haven't learned to copy them prior to posting).  Feel free to email or call if you want to talk more about the bedding compounds; I've done a lot of it.

5200: Not for use but for things that you never want to come off, nor UV stable.

4200: Similar to 5200 in mechanical strength, but still not UV stable

4000UV: UV stable, but not as strong as 4200.  More expensive

Regards,

T.