2 recore questions

[galleywench]

I am approaching the end of my marathon recore (in time, not work). I took this week off to get as much done as possible and I am getting pretty weary. 4 days of 8 AM to 10:30 PM is beginning to take its toll but I am making good progress and learning a lot along the way. Of course my dream of getting all the recoring done in one week is just laughable.

Anyway, enough rambling; here are my questions:

1. I just finished ripping up the starboard side deck and I am wondering if I should be putting cloth around the chainplates or if structural (aerosil) filler is adequate?

2. 1708 biax... 2 layers or 3? I just pulled the weights and plastic off the cabintop I did a few days ago and while it seems strong (still a bit green from this cold spell), the 2 layers are not flush with the surrounding area. Should it be?

Thanks for any help in advance... Dinner time and then back to the shed for me, I still have 12 feet of balsa to glue in tonight.

[Tim]

2 recore answers:

1. It depends on the size of the area. A small void, intended just to isolate the CP slots from the core material a small distance away from the slot, could be filled only with thickened epoxy, but a larger area would best be laminated from solid glass. If you are thinking of omitting core in, say, a 2"-3" wide by 12" (or 18" or 24" or however long your chainplate spacing is), I'd suggest solid glass for this application.

Either way, strips of HDPE or similar plastic, cut to the same size as your chainplates and clamped in place, make great avatars for the real thing to keep the slots in place and open during this process, eliminating the need to recut the slots later (which can be a pain) and leaving you with nice neat openings.

2. How many layers depends on how thick the new surface needs to be to match up with the adjacent (existing) areas. If 2 layers isn't bringing the surface flush, then you should add another layer or whatever you need: it should be basically flush when complete. Remember, you're replacing the laminate you cut out--no more, no less. If the original top skin was 1/4" thick, the new laminate should be 1/4" thick, or about 3 layers of 1708.

[galleywench]

Thanks Tim. Your like the Dr. Phil for people with boat problems.

[Tim]

If you keep up that sort of "praise" I will have to stop. I hate Dr. Phil.

[galleywench]

Just a joke... consider all Dr. Phil references stricken from the record.

[Rachel]

He says, mentioning him again ;)

[galleywench]

Sure enough, I added one more layer of 1708 and the cabintop is flush. It is still green, but the sound seems much more solid than with 2 layers. I had only planned on 2, but it's clear that 3 are in order. Guess I'll be ordering more glass.

[Figment]

strips of HDPE or similar plastic, cut to the same size as your chainplates and clamped in place, make great avatars for the real thing to keep the slots in place and open during this process, eliminating the need to recut the slots later (which can be a pain) and leaving you with nice neat openings.

Or strips of wood or whatever else you have on hand, covered in clear packing tape.

(not everyone has HDPE on hand, Mr. SuperShop!!!)

[Rachel]

That chainplate trick sounds nifty. So, if you use the plastic or wood covered in packing tape, you just proceed with your layup, not worrying about getting glass and resin on the avatars, and then you can simply pull them out later? Okay, that sounds obvious - and I have used packing tape as a release surface - but never with something that would have new epoxy trying to grab all four sides.

Or do you still try to keep from getting new stuff on the chainplates, and it's just for those few areas where you do get resin on them?

Rachel

[galleywench]

As a matter of fact, I didn't have any HDPE on hand and was going to coat my existing chainplates with pastewax (I think I read about this in Tim's Iota restoration page), but I had concerns with the pastewax smearing all over the inner skin when I put them in place. It seems like if that happened I wouldn't get a great bond around the chainplate area because of pastewax contamination.

I like the idea of packing tape especially since I don't have any HDPE plastic lying around... Time permitting, I'm going to test it out tonight.

[Drew]

I used saran wrap wrapped around my chainplates. Packing tape was not handy and it was. If I did it again I would do it the same way.

Drew

[Figment]

hmmm.... saran wrap would allow easier remover of the whatever upon completion. Nice idea.

Bear in mind that you don't want the hole to be precisely the size of the chainplate, you need some room for sealant, so a bit of thickness built up by a dozen wraps of plastic would be a good thing.

[Rachel]

And if wrapping in Saran Wrap.... I guess one could just use the actual chainplates? (Or is there something sinister I'm not thinking of?)

[Drew]

I used the actual chainplates. I wrapped the part that penetrated the deck with saran wrap and bolted the chainplates in before pouring the epoxy.

The chainplates were east to remove after the epoxy cured. The saran wrap sort of spiraled off since it could slide between the layers. A file made quick work of getting the last of the saran wrap out of the holes and roughing up the inside surface for good sealant adhesion.

Drew

[galleywench]

Sadly, I wasn't able to try out these methods last night, I'll have more time today.

Drew, I see you have an Alberg 35 listed as your boat. Have you done a complete recore/restoration? I'd love to hear what you've done.

[Drew]

I have not done a recore. My boats core is, thankfully, in fairly good shape. I have one area in the cockpit that will need to be addressed soon and a previous owner recored part of the cabin top but over all the core seems to be in good shape.

I repainted the non skid on deck last summer. I reinstalled the chainplates a few weeks back.Next is mast stepping and deck hardware.

I perused your blog, your work is coming along nicely. Keep it up!

Drew

[galleywench]

Ok, so I think I might have messed up a bit. I tackled the chainplate areas on the starboard side last night. First I wrapped each of the 3 chainplates in packing tape (clear stuff). Then I installed them and held them in place with a single bolt. Next I laid in 4 layers of biax with unthickened epoxy. Had dinner and waited for the epoxy to kick and then filled flush with thickened epoxy. All good....
Well, this morning I went back out and found that everything was still a bit green but certainly not sticky so I decided to pull the chainplates.

I think this is where I went wrong. I think I should have waited until it fully cured before trying to take them out because the chainplates took some big chunks of epoxy off and generally left a really messy slot. The picture isn't very good, but I think you'll get the idea.

So I guess the question is: How much should I grind out before I can repeat the process (and leave the chainplates in until epoxy cures)?

[Figment]

Hard to tell from the photos, but are the missing chunks greater than 3/16" in any direction?

If not, then do nothing. You'll want to chamfer out about that much as a sealant bed anyway.

If so, then still don't do much. Clean up the chunked-out area with a chisel or something, reinsert the chainplate, and patch in a little bit of goo. no biggie.