latent defects in the deck- how bad are they?

[kenny]

Surveyor discovered- through a percussion test- 3 different 4" x 4" areas of delamination on the deck of the 2000 cat 320 i am about to purchase. The areas showed no water seepage, nor are they located near any structural supports.. ie cleats etc... Surveyor suggested delamination was probably a fault in the manufacture. As I have read about delamination, or core separation- I realize it can be a serious and expensive thing to repair. The cheaper method was an epoxy injection- via holes drilled, the other involved much time and labor. How concerned should I be? The boat was pristine otherwise. The areas in question showed no signs of stress or cracking. Is this a deal breaker, or is this a fairly common phenomenon in used boats that is easily rectified? What should i expect in terms of repair costs? any help would be appreciated...thx

 

[David Foster]

Easy repair

Cutting back a section of fiberglass to replace or relaminate the core isn't very difficult, or even labor intensive.It's certainly not a deal-breaker in my book.I'd get a quote from a good fiberglass shop, and get the price reduced to cover it (and any other real issues from the survey.)Then I would drill a small test hole in the middle of the worst delamination. If the wood came up bright and clean, I'd inject some epoxy, seal the hole, sand it flat, and forget the whole thing. As long as there was no evidence of rotting core, or structural deformation of the fiberglass I doubt it's a big deal.DavidLady Lillie

 

[Warren]

Deck Repair

Drill several 1/8" holes around the edges and in the center of the effected areas. Purchase a can of "non-expanding" insulation foam (Home Depot, Wal-Mart etc.). Inject the foam into the center holes until it comes out the holes at the edge. After the foam "sets-up", drill out the holes to the depth of the fiberglass deck (1/8"+-) and fill these holes with Marine-Tex. Use automotive touch-up paint to match to deck color.Good Luck!

 

[Gord May]

Bad Advice

Sorry Warren, but I would NOT advise the use of "non-expanding" insulation foam for cored deck repair!More later...Gord

 

[Allen]

Ditto

Kenny,I agree with Gord. Whatever you do, stay away from any kind of foam repair, or any other repair that calls for non-marine materials. Keep in mind that any repair needs to do 3 things:1. Provide the structural integrity of a non-delaminated hull;2. Fill in any voids to prevent the ingress of water and/or moisture;3. Be permanent.Inject epoxy, not foam. Foam will neither fully fill the void, nor increase structural integrity. Also, it probably won't be a permanent solution.Go with epoxy. If you're not comfortable doing it yourself, hire a good fiberglass guy. It's not that tough. Be sure to document exactly where all the voids are with the surveyor to make it that much easier for a hired fiberglass guy to do the repairs.Either way, it wouldn't be a deal breaker in my book, either.Good luck!!!Allen Schweitzers/v FalstaffC-30 Hull# 632

 

[Gord May]

Epoxy injection etc...

The strength of a Cored Laminate (sandwich) structure is dependant upon a near-perfect bond between the outer skins and the interior core, and (to a slightly lesser extent) upon the structural properties of that core. Special bonding agents are applied to the core-skin interface, when foams and plastics are utilized in manufacturing cored decks (etc). This insures a cohesive (monolithic) structure.There is no assurance that an injected “consumer” foam will properly bond to the skins, nor that it will have adequate structural properties. Additionally, any unanticipated expansion (I know, you said non-expanding foam) could have disastrous effects!The previously suggested Epoxy-Injection methods are a much preferred fix for minor core rot or delamination. See WEST SYSTEMS “002-550 Fiberglass Boat Repair & Maintenance”, and the following article from “Epoxyworks Magazine” http://westsystem.com/ewmag/19/Replacing_Core.htmlI’ll have to admit that I’m not expert in the use of non-expanding polyurethane foam, but doubt that Home Depot & the like would carry the types of foam suitable for marine applications -closed cell -very high density 1 1/2 - 2 Lb is considered high, but would be way too light - I ‘m not certain, but think that 10 Lb is used to foam-in-place fuel tanks (power boats).- very low expansion rate 8:1 expansion is considered low, but would be way too much