Anchoring My Head

John S · Posted: Wed Nov 21, 2007 2:04 am Post subject:

Bob, I would assume my last post didn't make sense to you after all the bolt embedding advice you had given.

But.......if you look at the time posted you'll see we posted about 5 minutes apart from each other and I hadn't seen your post before I published mine.

Kind of interesting.

THANK YOU to Jim and Bob for resurrecting this thread. I now feel like I can tackle this project. (Although I'm still not sure I understand why I need the filler instead of just using the epoxy, I will look for some filler though)

Thanks again,
John

Adeline · Posted: Wed Nov 21, 2007 2:17 am Post subject:

Threaded-inserts

are one way of securing your head. Drill out the holes oversize. Bed the inserts into thickened epoxy(ala Dr. Bob). Secure with stainless machine screws.

ryder · Posted: Wed Nov 21, 2007 2:21 am Post subject:

drjohn71a · Posted: Wed Nov 21, 2007 9:01 am Post subject:

John,

The nature of the filler gives the final epoxy repair different characteristics. If you tried putting a lag screw into pure epoxy with no filler, it would probably split, shatter, or break off your screw. Unlike wood, pure epoxy does not have the plasticity to allow compression like wood fibers do. I guess a poor example would be that you'd have a hard time putting a lag screw into a hole in a metal block - the metal won't compress to allow the threads to grab 'hold.

The fillers allow sandability, workability and enough compression for screw insertion if the fillers are compressible themselves. My guess is that what you have can take screws. If nothing else, epoxy glue a block of strong wood in place!

John

matt_unique · Posted: Wed Nov 21, 2007 9:35 am Post subject: Wood filler

Speaking of wood fillers, for the purposes of overdrilling holes then inserting scews, etc. is wood flour as good as say cabosil?

When I built my dinghies I used wood flour to make filet's prior to fiberglassing a corner. Of course when making a natural wood finished dinghy the wood flour was perfect for blending.

Thanks

Sea Wolf · Posted: Wed Nov 21, 2007 10:04 am Post subject: Re: Wood filler

matt_unique · Posted: Wed Nov 21, 2007 10:54 am Post subject: Filler

Good point about the wood and water. Wood flour is very fine like a powder. I know the filet's held up like steel but I wonder about the impact of screwing into it as you point out.

I happen to have wood flour in the shed but it makes sense to get fine cabosil just to be sure of the strength and water reactions.

ryder · Posted: Wed Nov 21, 2007 11:36 am Post subject:

DrJohn

Thankyou. Your explantion was much clearer and more accurate. You are correct , the filler gives it different characteristics.

Jim D

John S · Posted: Wed Dec 05, 2007 12:41 am Post subject: One more question

I know, I know I've spent more time discussing this project than it should have taken me to complete it. But one more question.

I found a good source for those threaded inserts www.mcfeelys.com I was going to try some of these inserts without epoxy first. I have multiple thread type choices and was hoping someone could tell what type of wood C-Dory probably used for core material below my marine head. That way I can make the best thread choice.

Thanks