RE: Strengthening internal structures
I should have mentioned if you need the adhesive to "flow or float" into a hard to get-to area Epo-Grip's Clear Paste product does that job well.
As the product cures it heats up into a semi-sag consistency. That allows you to mix up the product apply it to an area then control its movement by tilting the project your reinforcing allowing it to float out into a perfect filet. The Clear Paste takes about 7-10 minutes to cure once mixed depending upon workshop temperature.