Virtually NOTHING will stick to HDPE except HDPE. If you're located
near a ski area or in the northern part of the US where skiing is done,
take the boat to a ski repair shop. HDPE requires an 'artist' to weld
the cracks, etc. with similar HDPE 'welding rod'. A local 'plastics
welder' can also do the same. Most other 'repairs' will soon fail.

Ignoramus32317 wrote:
In addition to my 21 ft boat, I recently found a 4x8 plastic boat that
someone put out as garbage. It is kind of doublehulled and seems to be
made of high density polyethylene (HDPE), like plastic buckets. I am
delighted because I can use this boat on some little lakes nearby.

It seems super safe (double hull) and super stable.

It does have however a few small cracks in the hull that need
repair. What is the right way to repair HDPE? Can I use glue guns with
hot melt glue?

i