I use to get them from a marine supply com. but they are no longer on eBay. I’ve haven’t purchased any from this listing. I haven’t been able find them any cheaper if you decide to go with these coils. Small discount for 2. https://www.ebay.com/itm/274365679727 Tubs
A "Boathouse Repair" is one thats done without having tools or the skills to do it properly.