The scoop on goop.

[PAComet]

Hi all- some questions on various appellations of epoxy. I have- some CPES, some Smith's Layup-Laminating, and a quart of Elmer's all purpose fiberglass resin from a big box store, and some 5200. I will also have some microballons to play with soon. The wood is wrc on a '30's comet. I will be

a) filling gaps without need of much structural strength
b) sealing new (and old) planks, areas around c.b. box
c) probably epoxying bottom (a la Trefethen's book)

I hoped to use the Elmers & ballons for filleting and "a" above.

I thought I'd use CPES to seal the non-weather side of the new planks, and also dousing some "slightly" questionable plank fasteners.
I was thinking I'd use the Smith's layup for plank seams.

I do not know if CPES would be proper as a initial coat on the weather side of the new planks and old before any fiberglass is on.
I do not know what real difference there is between Smith's Layup and Laminating Resin, the all-purpose Elmers (Borden), and epoxies I don't have (West/ system 3/ Mas).

The boat will be dry-sailed on freshwater lake. I am aware some would say keep it wet, don't mess w/ goop, and keep it "pure," but for this comet, it's either dry-sailed or bound for the great harbor in the sky.

Thanks

[Thorne]

Once nice thing about buying from small outfits like Smith & Co. is that you can call for advice, and Steve Smith will even talk to you sometimes if you have technical questions.

Check out Smith's website and Star Dist for info on how they recommend using their products -
http://www.smithandcompany.org/CPES/index.html
http://www.star-distributing.com/smith/products.html

My wife works right across the street from Smiths, and from what I recall they recommend using CPES as a primer-sealer underneath their epoxies. I've never used their layup epoxy but be prepared for long cure times and follow the directions exactly.

Don't know about the Elmers epoxy. Use the microballoons for fairing/smoothing, and sawdust or colidal silica for thickening epoxy for joints and fillets.

[StevenBauer]

I think the Elmers might be polyester resin, not epoxy resin. I'm afraid for that Comet. :(


Steven

[Thorne]

I think the Elmers might be polyester resin, not epoxy resin. :(


Steven

Uh-oh. I'd write that stuff off for boatbuilding and use regular epoxy -- the polyester resins reportedly don't stick to anything well including other poly resins.
http://www.boatbuildingonline.com/forum/viewtopic.php?t=632

Buying boat stuff at big box or auto parts stores can be done sometimes if you really know your products. Otherwise much better to support your local chandlery or quality hardware store.

[Bob Cleek]

Throw the 5200 and the poly resin in the trash... or save it for posterity. If you MUST sheath a hull, Dynel and epoxy is your best bet. CPES is a SEALER... use it on bare wood as a sealer.

If your '30's Comet is PLANKED (not plywood), you really shouldn't bother trying to sheath it. The planks move... the plastic doesn't. In short order, you'll have cracks in your sheathing, moisture will be retained and she'll probably turn to mush before the second Spring arrives.

[PAComet]

Thanks- sounds like the elmers is bad news- but one thing (among many) that Greenville PA lacks are quality chandleries. Main lake business here are pontoon boats. So I'll get west/system3/ or mas. Are there pronounced differences among these?
Bob- she is planked. And I have gone back and forth all year as I slowly root out the rot and corrosion on whether to glass her or not. But- caulking with oakum or whatever seems like a technical, precision type task, and also requires wood swelling I think- meaning long periods of being in the water. Yes she was designed for that. Sadly she won't get it unless I win the lotto. So Dynel seems best. INstead of 5200- you'd suggest what? Dolphinite? My learning curve is steep.

[Scott Rosen]

Have you considered splining the hull instead of sheathing it?

[Nicholas Scheuer]

Hey guys, "Goop" is a registered trademark for orange stuff used to clean grease and grime from one's hands.

Y'awl like wooden boats. So do I. However, I like fiberglass boats, too, and I kind'a resent laminating resins being called "goop" or "frozen snot".

Sure, Hereshoff, himself used the term "frozen snot". He was probably the originator of the term. Few others ever exhibit that degree of originality.

Laminating resins may be Epoxy, Polyester, Vinylester, etc. The laminating medium may be glass, Dynel, or a host of other materials.

Lacking a more precise term, building a "plastic" boat is as descriptive as building a boat from "wood". "What? Pallet limber? What kind'a wood?"

Moby Nick

[PAComet]

Splining is a possibility, but I know little on the process regarding particulars. My understanding is that you epoxy in thin strips in the seams- I'm guessing with the same type of wood as the planks. Do you keep the cotton-oakum or whatever underneath the splines? I've already removed significant amounts. Is splining the curved areas (where the planks meet the hard chines) difficult? I'd love to see a manual on splining to weigh that option.

One additional possibility has crossed my amateur brain. Originally, there was a doped layer of canvas between the double planks- of course this has turned to petrified rubbish by now. Would there be a modern material (rubber sheeting sometimes used as underlayment in roofing?) that could take its place, serving to seal the bottom effectively, negating the need for an outer layer of epoxy-fiberglass? Just a thought.

Lastly- don't be offended by "goop" (it is goopy). It also reflects my significant lack of knowledge- apparently I didn't know the diff between polyester and epoxy resins! But I learnt on a plastic sabot, then sailed for a decade on a Catalina 22. I'm just trying to get a working sailboat back in my possession...