I've used JB Weld for years fixing things and love the stuff. It will mend and fill holes for sanding and never gave me any trouble.
I just bought the J B Quik , sets in 4 minutes tubes. I don't know what 's in there but I had a serious allergic reaction to it. I mixed a small amount to fix something with a stick, scraped it on the item and smoothed it over. It took me 1 minute, never got any on my skin, only breathed the fumes a bit.
My eyes swelled up, I got itchy arms, had an asthma attack and felt horrid for 2 days.
I'm allergic to fish and wonder if it has fish oil in it like glues did 30 or 40 years ago.
Just thought I'd pass this on.