West has a wealth of epoxy-related info. From this page: www_dot_westsystem_dot_com/instruction-2/epoxy-basics/bonding-fasteners-hardware/
" Removing Epoxied Fasteners .... Remove a permanently bonded fastener by applying heat to the head of the fastener with a soldering iron or propane torch. Use a heat shield to protect the surrounding area. Heat will travel down the fastener, softening the epoxy in contact with it. At about 120°F the epoxy should soften enough to allow the fastener to be backed out. Allow more time for heat to travel down longer or larger diameter fasteners. " Adrian Humphreys Epilogue, Rockport ME C&C 33-2 adri...@telamontech.com > On Jul 21, 2021, at 10:48 AM, Bill Coleman via CnC-List > <cnc-list@cnc-list.com> wrote: > > To Dwight’s comment, unfortunately no, I can’t just grind it away and ignore > it, I am too Anal. > > The head was sticking out a couple inches (with an inch and a half in epoxy), > so that is what I was using to unscrew, as well as two lock nuts, so I had > two wrenches to unscrew with. Unfortunately, it broke almost flush with the > transom underneath the lock nuts. I should have lathered more Vaseline on it. > Don’t want to beat on it, as it is really in there, and beating would no > doubt break the inner and outer layers away from the foam core, and the > backstay is right about there . . . > > And thanks for all the suggestions, I have all the left hand drills and > easyouts, etc, I understand removing it like that is do-able, I just am to > anal to booger it up. That will be my last resort. I know there has to be a > way to heat the stud up. If I took a welder down, it would be fairly simple > to heat up, those obviously can take a direct short. And I have a half dozen > welders, but they are all 3 phase and not easy to drag onto a boat. I was > mostly looking for electrical advise. It sounds like the consensus is that > this 12V power supply is not something that can take a direct short. If I > can’t figure the bolt heating out, I suppose eventually I will have to try > the easy out or failing that rout out around the bolt. > > Like Old Lodge Skins, I will have to smoke on it till I figure it out. . . . > > > Bill Coleman > Entrada, Erie, PA > > > > From: ALAN BERGEN via CnC-List [mailto:cnc-list@cnc-list.com] > Sent: Tuesday, July 20, 2021 6:09 PM > To: Stus-List > Cc: ALAN BERGEN > Subject: Stus-List Re: Broken Bolt in Epoxy > > You can probably drive the bolt back through the transom using a hammer or > sledge hammer, and then a punch and a hammer. A hard strike should break it > free from the epoxy. If it's truly a carriage bolt, you don't want to try to > turn it. A carriage bolt has a round head and a square neck. > > Alan Bergen > 35 Mk III Thirsty > Rose City YC > Portland, OR > > > > On Tue, Jul 20, 2021 at 2:42 PM dwight veinot via CnC-List > <cnc-list@cnc-list.com> wrote: >> Can you just grind it away and leave it. >> >> On Tue, Jul 20, 2021 at 3:41 PM Bill Coleman via CnC-List >> <cnc-list@cnc-list.com> wrote: >>> I have a Broken ¼ - 20 broken carriage bolt with around 2 threads showing >>> out my transom. >>> 1 ½” is embedded in epoxy. An easy-out seems unlikely. I did four, three >>> of them unscrewed successfully, but apparently I didn’t coat this one >>> thoroughly enough with the Vaseline. >>> >>> I am thinking that if I can heat the bolt up to around 300 degrees or so, >>> it will break the bond with the epoxy. A soldering iron seems *maybe* >>> possible, but that is only one side. I was wondering if I could heat it up, >>> like plumbers do with welders to melt frozen water lines, it might be an >>> option. >>> But I don’t understand enough about electrical resistance to know how to go >>> about it. Using a battery for juice seems risky, having seen what happens >>> when I have shorted them out with a wrench – >>> I do have a 30 amp adjustable Powerwerks power supply, which seems a little >>> safer. >>> What I don’t understand, is if I can put a positive on one end of the bolt, >>> and negative on the other, will it heat the bolt, or will it just melt the >>> insulation off the wires? Or ruin the power supply? Or is it a factor of >>> the gauge of the wires? >>> >>> Bill Coleman >>> Entrada, Erie, PA >>> >>> >>> Thanks to all of the subscribers that contributed to the list to help with >>> the costs involved. If you want to show your support to the list - use >>> PayPal to send contribution -- https://www.paypal.me/stumurray Thanks - >>> Stu >> -- >> Sent from Gmail Mobile >> Thanks to all of the subscribers that contributed to the list to help with >> the costs involved. If you want to show your support to the list - use >> PayPal to send contribution -- >> https://urldefense.com/v3/__https://www.paypal.me/stumurray__;!!LIr3w8kk_Xxm!61cXmQ3t_0HBAdnGhtRD8lgVwNjDVtT-8uqhtSM8F0aVJFfk5eDfhB2Km5s1TBL1Vk8$ >> Thanks - Stu > Thanks to all of the subscribers that contributed to the list to help with > the costs involved. If you want to show your support to the list - use > PayPal to send contribution -- https://www.paypal.me/stumurray Thanks - Stu Thanks to all of the subscribers that contributed to the list to help with the costs involved. If you want to show your support to the list - use PayPal to send contribution -- https://www.paypal.me/stumurray Thanks - Stu
