Parting out H170 in AZ

[Hunter216]

Cool. Crowd thinking we are Yoda!

I have used a jig and a woodworking wide bit router for things similar, roughing in windsurfer blanks before glass. Think two rigid rails across the seat, pass the router through, shift a bit and repeat. Consistent depth removal based on the contour of upper most surface.

 

[BobbyFunn]

Cool. Crowd thinking we are Yoda!

I have used a jig and a woodworking wide bit router for things similar, roughing in windsurfer blanks before glass. Think two rigid rails across the seat, pass the router through, shift a bit and repeat. Consistent depth removal based on the contour of upper most surface.

Thats a good plan.

 

[BobbyFunn]

Got the bench glassed back in.

The next step is to fare the edge to the luran and do a light surface faring.

Fun facts:
3 layers of 1700 +-45 biaxual stitch matt totaling 40 oz of glass.
28 oz of epoxy wet out
9 oz of topcoat (2 layers)

I put down clear coat first to seal the foam and add some filler to the corners. I let that cure to a tack.

Added three layers if cloth with small batches of mix between, let that dry to a tack. Cut off the excess stitch matt while the epoxy was still "rubbery"

Added two coats with a tack between those. Cut off the packing tape while the top coat was still rubbery. No sanding!

There was some fish eye going on with the first clear coat to seal the foam. The fish eye occurred right over the cavities that were filled PL3X. The epoxy was glass smooth over clean foam. This may have been the source of the fish eye issues with the rudder mount and engine mount repairs.

No epoxy over glue. This may also been bad for the pucks if glue was not removed from the luran edges and not cleaned well.

I think when i was cutting the excess glass off the edges my wrist touched a tacky spot, because there was a little fisheye action going on and it was getting pretty hard by then as i was fighting a dull blade. The oils or sweat might gave contaminated that area. It glossed over nice on the 2nd coat. A new fush eye appear at the bottom edge, cant explain that one. It will be faired.

I will plan on doing the other bench the exact same way to keep the weight and look symetrical.

Lessons learned.
* Dont let epoxy touch the PL3X
* Cut the fiberglass matt to the exact size of the repair.
* Dont let body parts touch the surface. If body parts touch surface, then let cure fully to clean with degreaser.

Try to use poly resin. This epoxy $ is holding me hostage.

 

[Hunter216]

Interesting about the PL and epoxy thing. Small little areas in this job so likely no cause for concern.

Did you use the roller between each glass layer or after you got them all down?

The finished product looks amazing, shouldn’t take much to prep for paint.

Are you still going to create a groove between Luran and the new surface for the MMA “glue” joint or are you happy with the current bond now that you are finished with the FRP?

 

[BobbyFunn]

Did you use the roller between each glass layer or after you got them all down?

Pretty much used the roller nonstop. Would lay the mat down, gently roll, spread resin with a bondo squeezee, roll with much more pressure some more. I was as stingy as i could be with resin, while ensuring a good wetout.

My amazon order of 1700 mat was folded. They said folding is customary, bs. It was a stuggle getting the folds to not transmit up, even with rolling.

Are you still going to create a groove between Luran and the new surface for the MMA “glue” joint

You bet. After the luran is rounded off to blend with the fiberglass i will dremel a notch then back fill with The MMA. I wish i could have beveled the luran 6:1 and just glassed up and over.

Neat epoxy has the same coefficient of expansion as luran, that should work nice with the mma connecting luran and epoxy. Epoxy with glass has about 1/3 the expansion of luran. Hunter should have used some cloth in the luran matrix.

 

[Hunter216]

I know what you mean about the fibreglass “cloth” having a memory for creases. Much better to use it off a roll but small lots make that challenging.
Something I’ve tried and it helped a bit to “relax” the crease was to lay the dry cloth out and warm it carefully with a heat gun.

 

[BobbyFunn]

Took off the top of the port side bench. Its not impressive at this point or noteworty except for a couple items.

The bench was delaminating mostly at the area closest to the stern. No surprise, there is a bunch of blistering going on there. This area has a solid chunck of foam that did not react and foam up. This duplicated on the starboard section. This looks like where they injected the foam mix into the mold.

Lastly, this is where i used gorilla glue in an attempt to fix the delamination. For the repair i drilled a 3/8 inch hole, lifted the luran, pured glue in, then used compressed air to blow it around.

The gorilla glue only spreads about 3-4 inches from the hole then splits out into useless strands. The glue was holding up pretty good, but came apart easily when i lifted the panel out.

If making a delamination repair the best bet might be to jyst cut a huge panel out, and glue it all back down. Another alternative is to use a hole saw and cut out 50% of the surface. If you drill small holes and pour gorlla glue down, holes 6 inches apart shoyld work.

 

[Hunter216]

This area has a solid chunck of foam that did not react and foam up. This duplicated on the starboard section. This looks like where they injected the foam mix into the mold.

Interesting. I wonder what the manufacture process was. Spray mold release, layup FRP, put other half of mold on and inject the foam. Wait for that to set up, pop out of mold, spread glue and lay the Luran on, maybe heat so it conforms, not sure if the Luran step would need a mold press????

 

[BobbyFunn]

This shows a small scale version of vacumm forming.

Note how quickly the plastic wraps around the mold. Thats why hunter tried it. Someone was watching how-it's-made and imagined all the GRP layup staff they could repurpose.

There has to be a foam mold. Not sure when the fiberglass stitch mat is added, but it is well integrated into the foam. The symmetrical location of the foam "dripping" glob suggest it is not the usual random sloppy work.

If I understand hunter craftmanship, the only reason the stitch mat is there is to keep the foam plug from exploding then folding like a neutron star in the vacumm box. The stich mat/foam matrix is worthy of admiration.

Heres a hut tub version

 

[Hunter216]

Cool videos, wonder how many sheets of heated material they went through trying to figure out the correct heat setting. Pretty floppy stuff when hot.

 

[BobbyFunn]

Time for the luran replacement of the deck. At somewhat of a crossroad.

Here's what the OP provided, Post #11.

Here's what it looks like under the foot rest Post #38.

Im thinking i need to cut the foot rest off so i can have solid glass connecting both sides of the boat, a larger section of fiberglass connecting lots of foam.

Initially, i was going to cut completely around the foot rest, glue it to foam, then, reglass. When i raised the deck and fixed the crack in that area (still holding up perfectly) I never was able to raise the deck right up to the foot rail. Once i cut the luran, the foot rest will flop around useless and be nearly unsupported for about 2 feet. The irony is, the foot rest also is used to strengthen the flat luran panel.

If i cut 2 feet of foot rest off i will need to place something under the no foam area, then use the foot rest as a mold for the fiberglass, since the foot rest is kinda needed for sitting on the rail.

 

[Hunter216]

I’m not sure I clearly understand as I’m still trying to visualize this but....

Could you slide a rectangle of your printed circuit board material under the area of Luran footrest that isn’t supported?

The board is glued to the foam and would provide a stiff support surface to glue the Luran to.

That would leave the complete original Luran footrest in place.

 

[Hunter216]

The board is glued to the foam and would provide a stiff support surface to glue the Luran to.

Duh! You said there wasn’t foam here!! Sorry Unless you put some of your foam pucks nearby??

 

[BobbyFunn]

I’m not sure I clearly understand as I’m still trying to visualize this but....

Could you slide a rectangle of your printed circuit board material under the area of Luran footrest that isn’t supported?

The board is glued to the foam and would provide a stiff support surface to glue the Luran to.

That would leave the complete original Luran footrest in place.

The G10 would be very strong, but it is heavy and expensive. My new thoughts are to get some thin plywood, glass over it, cut it out to match the missing luran. The new deck is glued to the foam, almost level with existing luran. A layer of glass over all of that, bond the section to the luran.

The wood could go over the gap, the foot rest could be glued to the plywood deck.

Im googling the use of divinycell foam to make my own panels versus plywood. Plywood would be better for decking and all the walking on. Coosa board might be too heavy.

 

[Hunter216]

You might want to take a look at Kelgecell (sp) as well. I think it’s stiffer than dyvinycell

 

[Hunter216]

Are you considering integrating some hiking straps, since your redoing the floor anyway?

 

[Hunter216]

Lots of data here!!!

Foam Core Materials for Boatbuilding - 2

www.boatdesign.net

 

[BobbyFunn]

Lots of data here!!!

Foam Core Materials for Boatbuilding - 2

www.boatdesign.net

Nice! Bookmarked that one for later. Interesting about the polyiso foam (yellow with aluminum foil) that can be found in home depot is only good for insulation.

 

[BobbyFunn]

Are you considering integrating some hiking straps, since your redoing the floor anyway?

Considering all the time. Was also thinking about a traveller across the benches while it was being worked on. Thought a traveler built into the deck would be slick too.

Its a hunter 170. I'm really in this for the boat it is and the person who will buy this from me. For the sailing i do, the only part i dont like is the luran and the high freeboard. My crew is annoyed when i tell them we need to tack again so ricing this boat out is a waste if its usualy me singlehanding with three guests. The next buyer will want a dry boat that seats 4 very comfortably, can ride over big swells and doesnt need any work done.

 

[BobbyFunn]

Supplies arrived from US Composites for the glass and 4:1 epoxy kit. Port side bench is glassed in. Tomorrow after work will touch up with the disc sander. Still waiting for the 50ml glue gun.

This time after gluing the luran perimeter down with PL3X I cleaned up excess really well to avoid fish eye issues. The entire foam area was sanded with 80grit, vacuumed, then hit with compressed air. Rather than fill the holes with the excess I sealed the first layer with a runny mix of low density filler. Used a bondo squeeze and got it everywhere, supper thin where it was just sealing foam. Smooth enough to not have to wait for sanding.

It was game on with the 3 layers of glass and two top coats once the seal coat jelled up.

US Composite sent this glass on a roll. Much better. Total glass was 40oz, just like the other side.