[merc2dogs]

To support the balsa, rather than cutting props to size use a bunch of scrap 2x4 ripped down to about 3/8" or 1/2" thickness and some to 1/4 or 3/8.

Wear a hard hat when you put the balsa in place, then hold it with your head and place one of the strips across then spring a few of the other boards up to hold it in place. Put as many cross bits and springs as you think you need. The hard hat's easier to clean than hair, and frees both hands to speed up the work.

The strip across the balsa evens out the pressure so you don't get divots, and springing the strips in place to hold it works better than trying to cut a brace with an exact fit, and 2x stock is tons cheaper than buying dowels.
You can place them as close together as you want for more pressure if needed.

tape on the cross bits will prevent the resin from sticking if/when it starts to bleed through.
the spring makes it self adjusting so it takes up space as the resin levels out

Much easier to do it from outside.

You DO need two layers of fiberglass for strength. But the fiberglass can be built up in place, use "T" headed pins, or very short staples to hold it up, then remove the pins or staples as soon as the resin cures enough to hold the cloth in place

Ken.

 

[jbondy]

I suppose if the inside layer is as insubstantial as the OP states, it may not be feasible to do this from the top. I can't wait to see the pix!

 

[zz4gta]

I have some pix already on film, I'll see if I can't dig em out tonight. I'll be sure to bring a digital cam with me to get some before pictures.

 

[idontwantanaccount]

recoring from the inside

I have done some recoring work from both the inside and the outside. My experience is that recoring from the outside is easier, except that the finish work can take more time than you save with the fiberglass work if the area is small to moderate. If the deck is already painted, going at from the outside makes all the sense in the world because it is easy to match paint or repaint the whole deck. If you have original gel coat & molded nonskid on the deck the choice is harder. Work from the inside can typically be concealed by the headliner so a perfectly faired job is not necessary. To work from the inside, wet out the area with epoxy, then glue in the balsa with epoxy thickened with silica. A generous amount of thick epoxy should be applied the center of small to moderately sized balsa sections and pressed into place until epoxy oozes out the sides (Clean up with a plastic scraper). Brace in place using a piece of thin ply (covered with plastic) & numerous cheap pine battens from the local lumber yard (flexed into place). Laminate each fiberglass layer from the inside by wetting out the area and then waiting util tacky (e.g., after 30 min for 60 min pot life) and then pressing precut cloth sections into the tacky epoxy. Use a roller to eliminate voids and then paint on fresh epoxy for the next layer or finish coat. Use staples (remove as each layer kicks) or thickened epoxy if you have area that are problematic.

 

[zz4gta]

Thank you for that detailed response.

 

[mikehoyt]

interesting discussion.

Mike
J27 #150

 

[chucklesR]

ZZ,
If you can get the balsa core to set in place with thickened epoxy (and lots of patience holding it in place until it kicks) to hold you can put the glass back in the same way (i.e, half kicked thickened epoxy troweled on and push the glass into it. Do it in manageable sections and use a bunch of plastic thumbtacks/t-pins to hold it up until it starts to kick then use regular epoxy and a roller to wet the glass out. Leave the pins in place until it's solid, then grind off the heads and smooth the interior as needed. Finish it with paint or a vinyl liner if needed.
If you do it in sections you may want to do seams, or one big sheet over the whole thing. It's about strength not fracture lines.

If you really want to go esoteric - vacuum bagging won't work in your situation but a balloon might (blow up mattress anyone?) Test first, your results may vary

Remember the epoxy secret - epoxy doesn't stick to wax paper or waxed surfaces. Use liberally, often and before you THINK you need it.

 

[sailingdog]

I would highly recommend doing the repair from the topside, not from the bottom. First, getting a properly laid up laminate without voids is much more difficult from the bottom—since gravity is working against you. Second, you have to really be careful when glassing inside the boat or you can make a really amazing mess...that will take forever to clean up—which isn't the case when working from the top down. Third, it will go much faster if you work from the top down. You also do need to put a layer of fiberglass on the side you're working from—since that is what gives the cored laminate its strength, as others have stated.

The way a cored laminate works is that the two layers of fiberglass act as the top and bottom of an I-beam effectively, one in tension and one in compression with a stress web, the core material, between them. This makes it far stronger than solid laminate of the same weight would be. Not glassing the interior will result in a one-sided I-beam...which is pretty weak.

For core material, I'd go with divinylcell or Airex foam rather than balsa. It is probably going to be a lot easier to work with. ContourKore balsa is great to work with, but have you priced it recently???

 

[zz4gta]

Yes I've checked the price of those. Its more than a $1 per sq ft increase over balsa. Marine plywood is by far cheaper. Then balsa, then the foam as far as price goes.

 

[NOLAsailing]

I'll say again that the scope of the area you're recoring is too big to do from the inside. I sincerely wish you good luck if you go that route, but I don't see a repair stretching from the companionway to the foredeck ending well.

Much of the repaired area will be under non-skid, right? Non-skid is very easy to paint with durable products like Interlux Interdeck.

 

[sailingdog]

Yes, but ease of working with it may more than make up for the price difference.

 

[zz4gta]

Yes, but ease of working with it may more than make up for the price difference.

Not sure I follow. How much different is it going to be working with a plastic/foam core as opposed to plywood?

 

[sailingdog]

Balsa and Plywood don't bend—foam does, at least Airex does, Divinylcell less so. Most cabin tops aren't flat, so some curves are needed. IIRC, ContourKore balsa is pre-cut with kerfs in it so it can be somewhat more flexible than plain balsa would be.

 

[motovationcycles]

Deck core

Trevor,
Like I told the guy in the other thread. I have over 15 year professional experience with these type of repairs. your boat is not very far from me. Give me a call at my shop:
Motovation Cycles & Accessories 301-472-1811. (Let them know when you call it is about my boat, They screen my calls from all of the telemarketers).I will be glad to have a look at it with you and get a game plan togther. I am sure we can swap some labor back and forth between our boats!

 

[chucklesR]

Ditto on the labor Trevor.
I got a bottom to do and a locker to re-floor and re-glass.
It's always easier to measure twice when there are two people.

 

[donhaller]

That goes three times Trevor. Dan and ChucklesR, I'd be glad to help out with any of your boat chores. This will help me learn to do the work on my own boat.

Send me a PM when you need some help!

 

[Capnblu]

Too bad you guys don't live in BC. Try re-fitting a Tayana 42 with two artifical hips, on your own.

 

[zz4gta]

Thanks for all the offers of help, I'm reading over the requirements for the fillers and resins now. Trying to decide what's the best to use. I'll probably use the West systems, but not exactly sure of everything I'll need. I've been reading their website.

Trevor,
Like I told the guy in the other thread. I have over 15 year professional experience with these type of repairs. your boat is not very far from me. Give me a call at my shop:
Motovation Cycles & Accessories 301-472-1811. (Let them know when you call it is about my boat, They screen my calls from all of the telemarketers).I will be glad to have a look at it with you and get a game plan togther. I am sure we can swap some labor back and forth between our boats!

Thanks for the offer Dan, I'm actually going down to the boat this weekend. Helping a friend move on friday, and sailing on saturday. Do you work on saturday? BTW I'm more than happy to help out others on their boats, and have connections to a machine shop if you need some strange parts. I'm a certified automotive machinist.

 

[motovationcycles]

Saturday

Thanks for all the offers of help, I'm reading over the requirements for the fillers and resins now. Trying to decide what's the best to use. I'll probably use the West systems, but not exactly sure of everything I'll need. I've been reading their website.

Thanks for the offer Dan, I'm actually going down to the boat this weekend. Helping a friend move on friday, and sailing on saturday. Do you work on saturday? BTW I'm more than happy to help out others on their boats, and have connections to a machine shop if you need some strange parts. I'm a certified automotive machinist.

My shop is open From 9:00am to 3:00pm Saturday. Give me a call I Will come over and take a look. By the Way I went sailing yesterday. Tried out my "Victoria" remote control Sailboat my wife bought me for Christmas.

 

[idontwantanaccount]

material

The contour-core balsa works great for curved surfaces. Just remember to fill the kerfs before applying. FWIW you can also bend ply over curves that aren't too radical--just lay up 2-3 of thinner sheets to get the requisite thickness instead of one thick sheet. You could also kerf yourself or apply in smaller squares. Another couple of thoughts for you... if you are using the West epoxy, the gudgeon bros (West system) people are great resources if you need some advice on the project--just give them a call. Also if you do end up doing it overhead you could do it sections. Just be sure to prep properly and overlap layers of glass. You might also think about using stainless/monel staples to fasten the inside cloth layers to the core and not have to worry about grinding off or removal.