Looks like fixing it might be futile. Appears to be more cracks forming. I don't think I have a tank like that but I'll check and see. If I do have one in good condition I'll send it to you.
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My Toro snowblower with a Briggs and Stratton engine had a recall for cracked fuel tanks.
Even though I sent in the registration card, I was never informed by the manufacture.
One day, noticed the garage stinking of gasoline.
While researching to find a part number, found out about the recall.
Talked to three different Authorized Toro Service Centers before I found one willing to swap out the tank at no charge.