Glassing advice

[yeller]

Sooo...it's getting warmer and after having months work on the boat....I have done nothing and left it to the last minute (as usual). :rolleyes:

I have a couple glassing questions.

Question 1: I have the engine out of my boat and want to reinforce certain areas. Can I just rough up the gel and glass right over it or do I have to completely remove it?

Question 2: I removed my bennett tabs and now have some holes (1/8" up to 1/2") on the transum I need to fill. What's the best way to fill these and prep them for gel?

Thanks,
Glen

[gcarter]

Ya really need to remove the gel and/or paint before doing anything.
If you're going to install larger tabs, the transom needs to be reinforced. Maybe 2 or 3 courses of 1708 laid in. Before doing so, you could use a large countersink in a drill and taper the existing holes from the inside and fill the holes w/some glass cut fiber reinforced polyester putty.

[Carl C]

Have fun ;).

[yeller]

Thanks George. I was hoping because the gel is bonded to the glass that I wouldn't have to remove it.

....and Carl, thanks, but I don't think it is going to fun :nilly:

[yeller]

All good points Fix. I'm well aware of the need for the shop vac. I had to replace the stringers on my 16. Didn't take long to figure out the shop vac was needed. :biggrin.:

The transom on my boat is already cored completely, so I didn't plan on adding another core. I did plan to add 2 or 3 layers of glass just to be safe.


Carl, looking at your pic, are those the "stiffening, mini-stringers" running the length of your bilge (as per Donzi's repair schedule)? Just curious because they seem further apart than mine. Yours would be the 3rd repair (other than mine) that I have seen and mine is the only one that has the stiffeners located where they are.

[Carl C]

[ QUOTE] Carl, looking at your pic, are those the "stiffening, mini-stringers" running the length of your bilge (as per Donzi's repair schedule)? Just curious because they seem further apart than mine. Yours would be the 3rd repair (other than mine) that I have seen and mine is the only one that has the stiffeners located where they are. [/QUOTE]

Yes. The two mini stringers along with the fillet along the main stringers and all coated in glass made up the factory reinforcement. There were several versions, I'd like to see a pic of yours.

[ QUOTE] so your saying that the whole transom is cored all the way from one end to the other and not just the center? [/QUOTE]

Fixx, yes, the later models are fully cored with a synthetic material.

Here are some pics of what I did. I didn't core the bottom because I did not want to make it so thick that water could not drain from the front of the hull and also because it has already been beefed up with the factory mini stringer system. I worked around the factory transducer. There is a thread here somewhere detailing it all. You can get it done pretty fast but that bilge coat took forever to grind off! Don't forget to monitor the temperature when you are laying the glass. Fixx knows how to do it as do some others. George guided me through the process and he also has a lot of knowledge on glass work.

[yeller]

Yes Fixx, as Carl said, my transom is fully cored (approx 2 1/4" thick) in its entirety.

Carl, not the best pic, but you can see how my stiffeners are closer together.
The Donzi repair schedule showed that the stiffeners should be placed at 7" as measured from the stringer to the starting (thin) edge of the stiffener. This is how mine was done. Others I have seen (including one done at the Donzi factory) are placed 7" measured from the stringer to the outside (or thick) edge of the stiffener.

Others have had issues with cracking re-appearing, but I have not had any issues with mine.

[Carl C]

"Others have had issues with cracking re-appearing, but I have not had any issues with mine."

I haven't had anymore problems either :).

Thanks for posting the pic. Interesting variation but I guess it really wouldn't matter a whole lot.

Why the big notch in the stringer? That's not doing anything for strength!

[zelatore]

"Others have had issues with cracking re-appearing, but I have not had any issues with mine."

I did. My boat had the stringer mod when I bought it, along with a cradle. I don't know when it was done or why (stock 502 boat, 2001) but a couple years after I bought it I noticed some tiny hairline cracks on the bottom under the stringers. In theory, they could have been there when I bought it as they are hard to see unless you take a bright light and crawl under the boat, so possibly both I and the surveyor missed them. Or possibly they showed up after I began running it.

Very minor, but they make me worry about what could be in the future.

[Carl C]

"I did. My boat had the stringer mod when I bought it, along with a cradle. I don't know when it was done or why (stock 502 boat, 2001) but a couple years after I bought it I noticed some tiny hairline cracks on the bottom under the stringers. In theory, they could have been there when I bought it as they are hard to see unless you take a bright light and crawl under the boat, so possibly both I and the surveyor missed them. Or possibly they showed up after I began running it.
Very minor, but they make me worry about what could be in the future."

They start out as very hard to see hairline gel cracks. You need to look close with a bright light. Yours was not one of the models with issues so hopefully it is just cosmetic.

[gcarter]

Other years had issues though. My '88 TR had issues which I covered in my thread. And even though there're considerable differences in construction techniques from one series to another, the cracks prevailed........but shouldn't anymore.
I essentiallly did the same repair as the factory guidelines, but w/o the smaller pieces of foam as my stringers are closer together.

[JayZ]

Should I add any stringers or extra glass anywhere in my engine bay? I had some seemingly cosmetic gel coat cracks that have since been repaired as can be seen in the pic.

We sounded everything out and it was all good and solid and dry. ...boat is '93 Donzi by Chris Craft.

70487

[yeller]

Carl, notch is for the procharger. The 496 kit mounts it down real low. Stringer is pretty beefed up around that area so I'm not worried about strength. I've had a couple respectable glass guys/boat builders look at it and they both said it was no big deal. It's pretty much a mute point now though. With the new engine, the S/C will be mounted higher, so I'll replace the missing stringer section.


...not ignoring your question JayZ. I just don't have an answer for you. Hijack all you want. I don't mind.