Transom repair

[XstreamVking]

Hows the compression strength?

[W2F a V-King]

Which of the H80 foams did you use ?? sheet ?, perforated ?,contoured ?which one ? you got the H80 part spot on ! AND what thickness ??
What was your list of ingredients for your bog mix ?? This could be VERY HELPFUL for other people that are always looking for answers as to what to use !!

I did some comparison of density and tensile strengths between the Diviny-cell H80 and the Corlite pet in the same thicknesses, and found the Corelite about 1/3rd stronger, and @ $2.31 per sq/ft. in 1/2 thick for core replacement. Much more reasonable in cost. At about 1/3rd the cost.

I am doing some "testing" with samples received Saturday in the mail. I like what I see, but will reserve judgment until I see how well it adheres to a piece of fiberglass.

Also like the look and feel of the Corlite board 25-30 lb./ft3.
Going to do an adherence test on it as well. It looks like you could drill and tap threads (don't know why you would do this, but it gives you an idea of it's density)...don't know yet, but will find out. At 2" thick it's just under $12.00 per square ft. Very strong stuff. So for a transom piece 18"x41" that works out to just over $60. Compare this to Coosa board?

Will post results when done.
I am hopeful, but we will see......


James H.

[W2F a V-King]

Hows the compression strength?

Yes, just now went back and compared those numbers...had to use a conversion chart MPa to PSI. One set of spec's was in PSI (Corelite Pet) and MPa (Divinicell).

Compressive strength for Corelite Pet 228 PSI
Compressive strength for Divinicell H80 203 PSI

Compressive strength Modulus Corelite Pet 17,727 PSI
Compressive strength Modulus Divinicell H80 13,053 PSI

Honestly...I don't know what Modulus means, but will google it..................after I have a beer

Xstream, please feel free to double check me and my before beer math...
Another set of eyes on this is a good thing, specially a guy that knows what he's looking at...

I'll attach both PDF files....one from each manufacture.


Cross eyed and thirsty now . Off to the fridge

James H.

[XstreamVking]

I have a feeling, and i'm not downing the corelite at all but when the coosa or divinnycell has some glass on it the compressive strength will go way up. And as far as adhesion, both will have to be sanded for the best grip. The core lite is plastic and contains oil, so not ever gonna get as good a bond imo. So it comes down to is it good enough? I would say yes.

[W2F a V-King]

I have a feeling, and i'm not downing the corelite at all but when the coosa or divinnycell has some glass on it the compressive strength will go way up. And as far as adhesion, both will have to be sanded for the best grip. The core lite is plastic and contains oil, so not ever gonna get as good a bond imo. So it comes down to is it good enough? I would say yes.

That's good to know. Hadn't thought of that. I'm using epoxy if that makes any differences. Corelite claims no problems with adhesion with all 3, polyester, Vinyl Ester or Epoxy.... but if it has oil in it, that does raise a question.

I did get my samples from them and the Corelite board, 25 or 30 lb./t\ft.3 is pretty impressive. I will be bonding/glassing my stringers to it. Isn't polyester or Vinyl Ester petroleum based?

Guess I need to contact Corelite and ask some more questions. Great customer service. Easy to talk to.

Will let you know how well or not it sticks to each other.

Thank you,

James H.

[XstreamVking]

It would be easy to equally grind both coosa and corelite pcs. and then lay in 1 pc of 1.5 oz glass with the resin of choice, clamp for a few days then try and break apart with a chisel on the edge and see which one keeps its bond and which releases.

[blacktruck]

Oh yes you can make boats without cores and you don't need wood anywhere !!! as
in no where at all !! This has been going on for a longtime and even the chinese know better than to use wood for stringers and transoms as they rot out and soak up water and get heavy !

Too heavy, agree on the no wood but all fiberglass would be inferior to a proper core / sandwich construction.

[blacktruck]

Pads ! why do you need a pad and all the instability problems that go with them such a chine walking and having to load everything in the middle of the boat !
Oh sure its fun to go fast balanced on the pad and at the slightest puff of wind coming from the side and oops time to change undies !
If strakes had the same wider flats area equal to what the pad would be they are much safer and stable ! the sharp vee of the keel cuts the water and tracks straighter with two widely spaced stakes that are going to steady the hull . Sure you going to be a couple of mph slower but Id rather live to enjoy my day boating not having you heart in you mouth every time you go fast !!

Hate to rehash this old part of thread but this site should be educational and this is worth addressing. Pad bottoms are faster and safer than a sharp v keel in many applications particularly light fast boats. Pads actually prevent chine walking, whereas v's chine walk certainly and can't be aired out like a pad. Chine walking with a proper pad bottom is usually caused by lower unit drag, excessive weight and poor driving, among other things. Look at all of the best hulls out there, they all use a type of pad bottom. V's can be fine in some applications and especially heavier off shore boats that don't air out, but Pads are safe, fast and stable.

[tunnels]

Hate to rehash this old part of thread but this site should be educational and this is worth addressing. Pad bottoms are faster and safer than a sharp v keel in many applications particularly light fast boats. Pads actually prevent chine walking, whereas v's chine walk certainly and can't be aired out like a pad. Chine walking with a proper pad bottom is usually caused by lower unit drag, excessive weight and poor driving, among other things. Look at all of the best hulls out there, they all use a type of pad bottom. V's can be fine in some applications and especially heavier off shore boats that don't air out, but Pads are safe, fast and stable.

Thank you for that insight I had forgotten all about !! me im into tunnels and never experience such things because they get completely airborne most of the time !

[blacktruck]

Thank you for that insight I had forgotten all about !! me im into tunnels and never experience such things because they get completely airborne most of the time !

What boat is it? Let's see some pics.

[Ramonepb]

Pics of my Kona are on page one, what do you think of it?

[Timothy Hoffman]

im removing my trans from the inside on friday,do i want to leave any of the old glass around the edges when i cut it out or cut all the way to the edge ? i have only helped with a trans. never done one on my own.any advice would be appreciated

[XstreamVking]

Take it all out and start out fresh. Grind back to the good solid glass wherever you plan on repairing.