Core bonding options.

[wanagofass]

I'm about to start a Hydrostream record and am hoping to get info from people who have done more research than me on the best option to bond Divinycell core.

[XstreamVking]

What resin are you using?

[wanagofass]

I was hoping you'd chime in. I've got a good bit of experience/practice with polyester, so I'll probably just stick to what I know.

[XstreamVking]

You can use core bond or divelette brand bedding compound and it will work well for you. I would step up a notch to a vinylester resin (works like poly) and 1708 biaxial glass for a better bond and more strength. HS-80 x 1/2'' divinnycell core has higher physicals and is scored for easier placement.

[wanagofass]

The scored version is the one I was referring to.

[W2F a V-King]

I am not experienced, XstreamVKing is the guy to listen to.

When I did mine in my V-King, it was suggested to me to drill small bleed holes every 4-6 inches or so in the Divinycell to allow the excess bedding compound to easily get out and allow the core to lay flat. IIRC I drilled 3/16" holes. Kind of a PITA to do ....

I used H-80 scrim backed and scored as well. Used a roller to get it to lay flat, and did have the excess bedding compound to ooze up out of the bleed holes. I am sure an experienced man can do it without the holes, but it allowed me to get the Divinycell to lay flat as could be.

You going to post up some build pics???

Not sure of you can see the bleed holes in this picture....

[XstreamVking]

There's a lot of very good glass guys on here. I am only one of many that know how to re-build a boat. Several view points are always better than one. All the guys that have glass experience please contribute your knowledge to these glass and composite section projects....

[Noah Burns]

Xstream, when laying divinycell down, what process would you suggest? I've heard a couple different methods. I talked with my Dad and his only suggestion is to bag it as to get equal and constant pressure across the surface area.


1708 between deck surface and the divinycell material? what about over the top of the d-cell, anything?

[XstreamVking]

If you grind out some of the hull when you remove the old core, (almost always do) then use a layer of 1.5oz matt to replace what you removed. Also will give the new core a good uniform surface to stick to. I use the old way of putting a thin layer of putty on the core and a thin layer on the hull. Then roll, (with a dry paint roller and glass laminating roller) and press the core into the putty untill some starts coming thru the grooves and out the edges. (vent holes help) You want a 1/16'' to a 1/8'' layer of putty under the core. Don't want to squeeze all of it out, just the air pockets. Cover it with some wet 1708 and cover the edges of that glass with some 1.5 oz matt. (saves some grinding later and makes a stronger bond line imo) I'm an old glasser and havent had much vac bag experience. It is not too complicated to do after you aquire all the equipment and needed matl's. though.

[Noah Burns]

'Stream, you saying put down the putty then lay the d-cell on that and 1708 o top of the d-cell covering in squarely. The 1.5oz mat only used to tie the 1708 in to the deck or hull itself to complete the closure?

[XstreamVking]

Yes The process is called "tailing". It is used to cover the raw edges around the perimeter of a knitted material like 1700 bi ply or woven roving etc. 6'' wide torn matt strips are about the right size. Cleans the edges up, and eliminates any loose fibers to increase strength. Edit.... I like to go past the edge of the core by about 3''-4'' with the woven glass then add the matt.