Removing glued fasteners from decks

I have a vintage President trawler where my Vee birth ceiling has just started to leak. I am researching rebedding the hatch and looking at the stanchions. What I uncovered was that the PO has used an adhesive as a sealant on the screws to deck hardware, railings and stanchions. These are not through bolted items where bedding works best. The deck has a double layer so the entry point of the water will be an exhaustive search. From the outside there is gelcoat, fiberglass, 2" thick cored foam, more fiberglass, 1/2" foam and then the headliner

Is there a good way to remove these screws with snapping the heads, UGH !
Can I use heat with a soldering iron or a solvent to soften the adhesive. Hopefully it is not 5200

5200 will soften with heat

We also have a President 41. We have had many leaks. You can use heat to loosen the adhesive. If it 5200, there is a product called Debond that is supposed to work on 5200. I have not used it. The screws will probably back out even if it is an adhesive. The problem will likely be trying to pry up the fitting. That is where they say Debond will help.

In searching for our leaks, I have removed the 4 windows on the cabin sides and glassed them closed. We removed the hand rails on the cabin top and epoxied the holes closed. I added 3 ventilation hatches to compensate for the loss of light from removing the windows. I also have overdrilled and reefed out the coring then filled the holes with thickened epoxy in the forward deck fittings.

We put a hardtop on the flybridge and modified the enclosure to stop some of the leaks around the flybridge. In the process we removed the sliding hatch on the sundeck hardtop and ground off the raised areas the the hatch rode on.

We have a couple of leaks in the aft cabin. The portholes were leaking. The gaskets appear in good condition so I put some covers over the portholes that let in light and air but stop rain from getting to the ports. We caulked along the teak toe rails from the bow to the stern. The old caulk was applied on top of the varnish and when the varnish failed the caulk let go. We sanded the teak down to bare wood. Applied a Sika primer to the teak and used 291 to caulk the joint. We are in the process of painting the flybridge, cabin sides and decks now. We are going to launch next Wednesday so we will see if all this work has helped or not...

I have used Debond, it does help. It is best to apply then with the tip of a knife work it in to the joint so it can penetrate better, pushing, and prying the part eventually comes off.
Careful with the knife, I wasn't one time and wound up with 5 stitches in a finger!

I put all my outside screws in with epoxy. It eliminates screw leaks. I use a power hand tool with a impact head to remove glued and epoxied screws. Impact tools will usually remove stuck screws and bolts where hand tools either destroy the threads or twist off the head. Since I started using these tools, I rarely use a hand screw driver.

Might try heating a screw driver tip red hot then holding to the screw head.

Remove the wood and use vicegrips on the screw.

Heat the fastenings, say, with a soldering iron, if simple force doesn't do it w/o wringing them off.

Time is your friend.

Any pry that tensions the goop will eventually cause it to loosen.

May take a week but slow prying works.

Next time (yea there is ALWAYS0 a next time) try Dolphinite instead of glue