Removal and rebedding Portal

[Brightside]

Looking for suggestions to remove an 8" port light (plastic) that is glued in with 5200. I'm would like to get it out without destroying. Also suggestions for the best material to rebed.

 

[Comodave]

Try a heat gun and a sharpened putty knife. If that doesn’t work try DeBond. If that doesn’t work then you will probably have to destroy it. Good luck.

 

[firehoser75]

I had plastic Beckson 8 inch diameter round portholes. One was leaking. I found several good YouTube videos outlining how to change one. It was not that difficult. Beckson recommends using a special Dow silicone sealant as many sealants can damage the plastic port, or be difficult to remove (like 5200!!).
My new port has been in for several years and all is well.
I know many here will say NEVER use any silicone, however, this is what the manufacturer recommends, and they recommend against using anything else.

 

[FF]

SLOW is the key , a couple of putty knives slid in till there hard to push , then left o'nite , and some de bonding solution , may take a week , but not harm the port.

Plan B is to purchase a replacement , and return it if not needed.

 

[Marco Flamingo]

My prior owner had replaced two of the four plastic opening portholes with chromed bronze of the identical size. After purchasing, I found two more chrome portholes stashed in a locker. Good thing, as they were no longer available and the last list price I could find for them was $550 each.

Replacing with metal allowed destructive removal of the plastic ones. A really nice option if available since it is possible to spend several hours carefully cutting/dissolving 5200 and still break the plastic porthole.

I've given up on 5200 and some of the other expensive "boat" sealants. DAP Dynaflex is about $7 a tube at the hardware store. Comes in more colors than boat sealants. Water cleanup. So far, so good. Haven't had to remove any yet, but it can't be any more difficult/impossible than 5200.

 

[firehoser75]

5200 is not an appropriate "sealant" in most applications. It is very, very difficult to remove without damage.
In most applications involving fibreglass, I use Sikaflex 291 or the Sikaflex UV equivalent. In the case of the Beckson plastic port, I used what the manufacturer specifically recommended, otherwise I would not use silicone on the boat.
A bedding (sealant) material that I have not used, but have heard great things about, is Butyl tape. Rod Collins, a member here, sell a good quality product, and not all are the same. marinehowto.com