Core Sample Help Needed

[hardiek]

Can anyone point me to a good article on how to take a core sample? I am searching through the archives but thought someone might have a favorite post. Thanks in advance.

Kevin

 

[oops!]

Re: Core Sample Help Needed

hi.....welcome to i boats.....


core sample for foam.....

take a pvc pipe (approx 1.5 ins) and cut 2 "teeth" in the end of it.
use a hole saw and cut thru the deck...(floor)....insert pipe and using a "twisting motion" push pipe thru the foam all the way to the hull
remove pipe......examine foam in pipe for any moisture.

take several samples.



for wood....(stringers....transom....deck....ect)
using a smaller drill bit....place a peice of tape on the drill bit to mark depth of the wood....
for example....if the transom is 2 inches thick....place the tape at i.5 ins from the tip. drill into transom till you hit the tape....remove drill bit.

examine wood shavings for any moisture....

in both cases...."some" moisture is a failure.

repair of core holes.....
foam....

replace core sample.
replace the cutout from the hole saw.
seal with 3m 5200.

wood....
fill drilled area with 3m 5200.

cheers....
oops.

p.s.
search core sample.
tashasdaddy has detailed pics of a foam core sample pvc pipe.....
but you can get the jist from this post.......

remember.....any moisture is a failure........take several samples from different areas....on the transom.....under any thru hull openings

 

[hardiek]

Re: Core Sample Help Needed

oops!,

Awesome. Thanks. Will get it done this weekend.


Thanks.

Kevin

 

[hardiek]

Re: Core Sample Help Needed

Hey guys. Took my core samples and all was dry so that was good news. I was very happy to see no wetness. but i did have a question that came up as I did the core samples.

the boat is a 1994 four winns horizon 180. When I took the samples I noticed the stringers are all fiberglass stringers. how do those differ from normal wood stringers? I know they are fiberglass on the outside; what are the filled with on the inside?

Thanks for everyone's help. I am very slowly getting better at this boat restoration game.

Kevin

 

[Bob_VT]

Re: Core Sample Help Needed

You have about a 90% chance they are wood on the inside. People who core sample into those with a drill bit need to make sure they are properly re-sealed.

 

[hardiek]

Re: Core Sample Help Needed

You have about a 90% chance they are wood on the inside. People who core sample into those with a drill bit need to make sure they are properly re-sealed.

Thanks Bob. is there an easy way to tell whether they are wood or fiberglass. fyi, I plan to reseal the holes with 3m-5200 sealant.

Kevin

 

[Yacht Dr.]

Re: Core Sample Help Needed

hello hardiek ..

ermm.. if its all fiberglass stringers then why are you asking about cores ???

seeing as core samples are normally for hull or stringers..( which you said are fiberglass..then why ask ??

"the boat is a 1994 four winns horizon 180. When I took the samples I noticed the stringers are all fiberglass stringers. how do those differ from normal wood stringers? I know they are fiberglass on the outside; what are the filled with on the inside?

Thanks for everyone's help. I am very slowly getting better at this boat restoration game."

hmm..what are you wanting to restore ?

180 4W is simple.. your main question should be about outdrives and your motor..they cost more then the boat is worth personally.....

YD.

 

[hardiek]

Re: Core Sample Help Needed

hello hardiek ..

ermm.. if its all fiberglass stringers then why are you asking about cores ???

seeing as core samples are normally for hull or stringers..( which you said are fiberglass..then why ask ??

Thanks for everyone's help. I am very slowly getting better at this boat restoration game."

hmm..what are you wanting to restore ?

180 4W is simple.. your main question should be about outdrives and your motor..they cost more then the boat is worth personally.....

YD.

YD,

Thanks for the reply. Here is the deal.

I bought a 94 four winns horizon 180 with the interior needing replacement. I have never owned a boat before so found this site and asked some questions about how to restore the interior. The first thing that came up was to do some core samples on the stringers and the transom. I did the samples this weekend not knowing that the stringers were fiberglass (I think they are, but I am not 100% sure still). The core samples were dry, but they did not seem like wood (the drill bit went through very way to easily through an 2" stringer and I found no evidence of moisture whatsoever).

So I was asking how to tell the difference between wood and fiberglass stringers to verify they are fiberglass and make sure that I am on the right track.

If anyone can tell me how to tell the difference I would appreciate it. FYI, I plan to call Four Winns tomorrow to see what they say.

Thanks to all.

Kevin

 

[J. Mark]

Re: Core Sample Help Needed

The Four Winns stringers are not wood cored on my neighbors 1988 as verified both by core samples and the factory confirmed it by phone.

I suspect yours is the same. Transom is still wood though.

 

[bowman316]

Re: Core Sample Help Needed

in the back of the bilge, the stringer should run along both sides of where the deck drops down to create the bilge. I the very back corner, there should be a drain hole, which will let you stick your finger inside the fiberglass stringer "Beam". Then you can feel if it is foam or wood.

Mine were foam.

You may have to really have the floor removed until you can find a drain hole going thru the stringers.

 

[Yacht Dr.]

Re: Core Sample Help Needed

Hello again..

I did not mean to sound so...um..harsh or anything..

To tell the difference between wood/foam stringers is simple.. take a core sample. Simple.. take a 1/4 drill bit and drill through... if you see wood bango..if you see foamish powdery stuff .. foam..

here is the real deal m8.. if your really wondering about your stringers or transom then take a small hammer or even a wrench of some sort and start tap tap tapping away. you will Hear the difference in the "percussion" . If it sounds like a dull thud instead of rock solid ..well you will know. then you should take a sample in that area.

If you don't do this then you really have no idea what your sample is saying to the rest of the boat..

If you could find somebody with a moisture meter.. use the percussion test to find thuds..then meter it..then core sample it.

Simply taking misc samples here and there without some kind of direction is..well..not very productive..and could be misleading ..

Hope this helps more..

YD.