Bedding Silicon Bronze Hanger bolts

[David Geiss]

Good day wise Forumites:

I am bedding twin hanger bolts, of silicon bronze, in a mast step of mahogany on one of my sailing canoes.
Last week, I removed both and clean well with a Dremel driven wire brush.
Took a heat gun to both holes for a few minutes to to minimize and moisture that might be in there.
Dripped unthickened G-Flex into the holes, coated the lag threaded ends of the hanger bolts and installed.

One on the bolts is now rock solid and the other I was able to easily back out.
Is there any particular prep I am overlooking or perhaps a better adhesive to use in this application?

Thanks in advance.

Best,
David

[wizbang 13]

One might overbore the fastening hole, exposing new fresh dry wood, and fill with a slow cure resin.
Depending on , well, things, the bolt could be dropped into the wet resin, or one could wait until the resin hardens , and re drill for the threads.
I have not used G flex, but I can ;t see a problem with regular 105.

[Sailor]

I must admit I have absolutely zero experience with bedding twins. Let me know how it goes.

[SV Papillon]

Did the lag unscrew out of the epoxy? Probably cont oil etc on the metal so no stick, I would rough the lag portion up with 80grit clean with acetone then put some fresh resin in and try again

[eastern270]

I installed my stern bearing housing very similar way. I bored out 2 holes about 1" in diameter. I filled with thickened epoxy and milled fiberglass fibers. When it cured I drilled a hole for each hanger bolt and before screwing in I put a bead of 3M5200 on the lag threads. My bolts were 3/8" diameter. So far no problems. Hopefully they never snap or I'll have the reverse problem you have (trying to get them out). I actually installed my inboard engine the exact same way except I only put 3M5200 on the last 1/2" of bolt under the hex just to create a seal around the top.

[David Geiss]

I never thought of using 3M 5200 on the lag thread...thanks.
I took a fresh wire wheel (via Dremel) to all lag threads, then swabbed with acetone.
Then used acetone soaked q-tips to the holes and bedded the hanger boats again with G Flex, dribbled into hole and applied to lag threads with pipe cleaner.
That was last night...will give full 24 hours to cure and then we shall see.......
Best, David

[David Geiss]

Jeesh...I have one hole in this mast step arrangement that is giving me trouble.
I re bored slightly (going through the bottom of the hull trying as I did to avoid that).
Cleaned the re bored hole with acetone, placed abraded and cleaned lag end hanger bolt, saturated with expoy into the hole. No go.

Now I guess I will re-bore slightlt larger and fill with epoxy, and then re-drill for the hanger bolt.
Any purpose served in thickening the epoxy with any filler before filling the hole?

Thanks....learning something new every day.

Best,
David

[wizbang 13]

never mind "slightly" , bore it out to clean dry wood. what is "no go" ?
no acetone, no q tips

Use slow cure or cool resin so that it does not bubble up in the hole.
i would add some 403, not too much, still be able to run loosely.
Got pics of what's goin on? maybe something missing here.
I would not use 5200. Either drop them in the wet epoxy, or treat the cured epoxy like hardwood, bore carefully and put lanolin on the threads.

[David Geiss]

Thanks WizBang...no go meaning the fastener still rotates in the hole.
Already pulled it. Will shortly re-bore to dry clean wood as you indicate.

Based upon your comments re slow cure or cool resin, I am guessing that g-flex not idea here.
I have some Super Sap (Entropy Resins) and some MAS laying about but need to learn exactly what I have.
As you can see I am no genius re epoxies.
Maybe shoot an image or two later and post.
Many thanks.... David

[wizbang 13]

I have not used g flex,it may be "soft"for your job.Also,very small batches are problematic.Or,you have a contamination problem,thus,my zest for through over boring.

[David Geiss]

Been thinking about it some more. The upper portion of the mast step is mahog, the lower brown ash. The ash may have been a bad choice for a part having water slosh about it.