filler for foam core of Royalex?

[MotorCityOC-1]

So long ago I had this tear in the hull of my Ovation, along the leading edge of the vinyl patch of the R side thigh strap anchor. I figure it was from a sudden stop . It looked like somebody just unzipped six inches of the ABS on the inside of the hull, and I could pull it open and touch the foam core. I discovered it two days before a paddling trip, so I fixed it in a hurry. I put a 7" X 10" Kevlar felt patch over it, and paddled it for another season. It held up pretty well, and I thought it did the job...

Turns out, water has been getting in where the Kevlar has cracked. When I chipped away the old Kevlar patch, I discovered that a 7 X 10 chunk of the foam core has rotted out, in the shape of the patch.

The rest of the core seems okay. I don't feel any other pithy spots when I press on the bottom of the hull.

My plan is to fill in the core where the foam is rotted out (I cut out the questionable bits) and put a big 'ole patch of 1/8 ABS over the whole mess.

What would make good filler material to replace the rotted out foam core? I would use JBWeld or PC-7 if the area weren't so large. I am considering very 'resin light' kevlar felt cut to fit the hole, and maybe some of those itty-bitty pieces of cut up kevlar felt that John Sweet sells to fill in the blanks as it were.

It would suck to have to sand down a bunch of Kevlar prior to gluing the ABS. What if I glued the ABS and epoxy-ed the felt at the same time? What could possibly go wrong? Does anybody know if West System Epoxy and 3M 3532 Urethane adhesive do terrible things to each other if they accidentally touch?

Any other ideas for filler? Should I face facts and make a nice Ovation planter for the front yard?

Sincerely,
Indefatigable in Detroit

[MotorCityOC-1]

Please?

[sbroam]

Sorry, dude, I really don't know! I'd be careful not to make the "fill" too rigid, that could lead to stress at the edges where it mates up with the rest of the boat. If you are down to the inside of the outer ABS layer, maybe cement a couple of thinner layers of ABS (1/16th or less?) to that - I say thinner, one at a time, because you might make smoother transitions from the repair area over the area that still has foam core - lapping over a couple of inches over your inner layer of ABS. I'd seal the edge of your remaining foam core (with resin?) because if I remember right, ABS cement (largely MEK) is supposed to eat that stuff up.

Just an idea...

Scott

[MotorCityOC-1]

Thanks Scott!

Yeah, I'll take any ideas that come my way. This is THE BRAINSTORM part of the program. I am not a lawyer, and no one will be held responsible if I try what they suggest and the boat sinks

What about actually using some kind of foam. Anybody know about foam? What kind of foam is the foam core of a sheet of Royalex made of? If I knew that, I could better approxomate it.

Anyway Scott, I'm mulling over your idea. I hope that folks aren't holding back on posting suggestions just because they don't know anything- it's never stopped me before.

[PAC]

Well be careful what you ask for....

See if you can contact the manufactor (or maybe someone on this page with a DOA boat) who has a scrap of the core foam that can be cut. If you can cut that core to fit you should be able to ABS cover it.
Or, again this is scary astro-projection stuff, get one of the homedepot (god how I dislike that place - Walmart of home repair) blue insulation panels and cut and shave it to spec.
Then use shoe goop to attach it. I know its not the "best of" but your trying to get by.
Then use the ABS.
You might also use a peice of wax paper over the foam to protect it.
Both options are ugly but your a "pretty" good paddler so no one is going to blow you grief when you make those death ferries above munchie holes in a boat that looks like one of mine!
Besides I know you like to design on a dime!

[MotorCityOC-1]

Paul,

Louie has more boats than you. Are you gunna take that?

Here's what you do:

start buying up all the derelict boats you can fine. I'll start you off with a great deal on a gently used Ovation...

pm me for details,
K

[PAC]

Hummmm.... Nah you'd want too much for it!

I'll think more about your Ovation "problem"! I'm sure there is a better and cheaper solution!

As for having fewer boats than Louie.... I'm thinking about that one too! But I know for a fact Adam has many more than I as well! Now Louie - I really have to get my priorities straightened out!

CU on a river soon and bring that krazy kayaker with you!

[Roy]

I have used micro-spheres mixed with epoxy to form a bondo-like material for this application.

Remove all loose foam remains, paint the area where the foam used to be with epoxy (with hardner but no spheres) and then right away squeegie in the spheres/epoxy/hardner mix. After it gets hard, sand or rasp, and lay up the patch. I have never used an ABS patch over this mix, however (only composit patches).

[Louie]

If your in an ovilation, you need a new boat even if the hull on your was perfect.
The two years I was at Dagger that was the only open boat I go to frame in the mold for, One of the worse they ever made

[Louie]

You need a new boat, even if the hull was perfect, you need a new boat.

The whole two years I was at Dagger that was the only open boat I got to build a frame around the mold, thank God I got to work on the Quake frame, but like I said you need a new boat, try a Zoom if you have to have Royalex, I do have some canoe half You could peel the Vynal and ABS off of to get to the foam but It look like the same stuff Boogie board are made out of

[Louie]

was some serious lag time involved in this

[markdc70]

Even if you get a spare royalex piece and trim the foam out for your boat, because the foam wouldn't be fully bonded to the inner and outer abs you wouldn't have the strength of the "sandwiched" layup. It would still be a soft spot in the hull, unless you could bond these layers with something that doesn't eat them up.

[sbroam]

Does anybody know what the foam is? Is it foamed ABS? That would be consistent with the warning that ABS cement would eat it - the cement consists largely of a solvent for ABS. I agree - if the layers are not bonded, it would be significantly weaker than if they were. Building up a solid patch from the outer layer of ABS would probably be better than trying to replicate the previous foam layer. The foam layer only serves to separate the stiffer layers of ABS for strength and weight - essentially like the web of an I-beam. If you make it solid all the way through it will only make it heavier. I don't think that is your primary criteria!

[dixie_boater]

The foam core is made of ABS foam. MEK-based ABS adhesives will soften or dissolve the foam core of Royalex. It is very difficult to restore Royalex when the foam core has delaminated. I have never tried to fill the void left when the foam disintegrates. The foam core would be hard to replace. I am not sure what recommendation to make for Kevin. Any repair will be stiff and won't flex with the rest of the hull.


Kevin,

Is the damaged area on the side or the bottom of the hull?

[Louie]

MAKE A PLANTER OUT OF IT.