I always hear a rumour that the kiwis couldn't get a keel off a yacht after removing keel bolts the story goes they inverted the yacht and tried removing the keel up side down but still caused tug of war! Maybe why my head door is still stuck even although the screws are removed!

Righto I don't belive everything I hear unless I see with my own currently two eyes!

Depends which Sikaflex, some are sealers, some are glue/sealers. I bolted a large aluminium tank over the stern of my early fishing vessel and used Selleys silicone around the edge as well. When I came to removing it there was a large sealed section caused by the silicon. I had to use several wedges to work around and break the seal.

Sikaflex is not a silicon but has the same effect if there is a fair bit of surface area. Just ensure you use the correct product for the job.

My sliding cabin sliding hatch cover was screwed and siliconed. When it came time to replace the hatch slides the screws came out easy. The silicone...........

When I reinstalled the cover I did away with the screws every 3inches and instead just used them in each corner to bed the silicone down.