Deck Recore

Hey guys,

New to the forum here, I just started a project on replacing the core on my Perry 41 sail boat. I am up in the air about what resin to use, either vinyl ester or polyester? Other than the cost would it make that much of a different to re-laminate the deck in vinyl?

I am going to re-core with H80 Divinicell embedded with Core-bond B70...

I was thinking of going with a layer of mat on the lower skin, then core material, then laminating with mat to get proper thickness of the existing deck bevel. Any thoughts?

Thanks,
Pat

 

I use epoxy for all deck repairs.

Why did the deck delaminate ?

 

The previous owner/s did not take care of the teak decks that were drilled into the core. They were in bad shape when I bought the boat a month ago, the survey said that they had to be removed to check the condition of the deck.

I removed the teak and found that a river was running through the core. It is coming out easily, and some are coming out as a pulp because it is so rotten.

I don't want to use epoxy mainly because of the size of the repair, the entire deck is coming up and I think I will need over 15+ gallons of resin to re-laminate the deck...

 

Ahh. TEAK DECKS !!!!!!!!!!!!!!!!!!! six million holes.

Hopefully if you replace the teak deck you dont use any fastenings .

Dont know about material quantities...Ive never done a deck core that big..



Epoxy is the best...perhaps someone can advise you on best practice with polyester.

When purchasing epoxy in 15 gallon qualities you should be able to get a good price.

You should be investigating a vacum bag for bonding the foam to the deck and be sure to address all point load , core compression, and fastener insolation issues for anchor winches, genoa tracks....

Many teak decks age prematurely because dead water sits in the waterways . Deck drains or a molded covering board may be beneficial .

 

Hi Pat,
You might want to reconsider your laminate schedule...using matt exclusively as your material choice is going to add a lot of uneccesary weight without contributing much in the way of strength. How about throwing a in a few layers of 1708 Biaxle?

MM

 

The deck you removed looks like it was constructed with structural cloth, not 100 percent mat. You should contact an engineer to determine the new deck layup scantlings.

Since the deck is structural, you will need to overlap the new fabric some distance up the bulwarks and cabin house.

 

Thanks for the input, with further thought and maybe a typo, I was planning on laminating the deck with a biax with mat backing. I have left a 3 inch feather around the entire deck to laminate the "new" deck to. I have seen other people do this similarly and never heard of feathering it up the side of the house top?

 

You are on the right track, 3" is enough for the scarf, you dont need to use epoxy, yes its better but vinylester is excellent, plenty adequate and will get the job done quicker as long as you have adequate temperature. As far as the laminate goes if you take a piece of the old top skin and burn the resin out of it you can determine what the old laminate was, for the new laminate you are tied in to the thickness of the old one of you dont want a lot of filler, if you make up the same thickness with DB1708 and vinylester it will be at least as strong as the original. You could use polyester but as with most things, the middle of the road (cost and physical properties) approach usually makes the most sense.

Steve.

 

Im not seeing anything in the pictures to suggest any particular laminate, im guessing that it is mat and roving but if it was built in the 80s it could have biax in place of the woven.

Steve.

 

Steve, when grinding the scarf, it looks like mat and roving but it is hard to tell. The boat is an 81

When laminating it all back together, would it be best to use roving or biax or cloth? I already have a roll of 1.5oz mat from another job and would like to use it and I know that most roving and biax come with a mat backing... Any ideas?

Thanks,
Pat

 

Like i said, if you burn the resin out of a piece of the laminate you have removed you will know what was in there, you can even weigh the layers and get a fair idea of the fabric weights. However you dont really need to know this as you are more concerned with getting the thickness close so you dont have to use too much filler. If you have some 1708 biax i would use that since it has a 3/4 oz mat included. If all you have is mat and you need to buy structural glass you could buy 1700 biax rather than the 1708 so you can use up your mat, i wouldnt buy roving, i dont know why they still make it .

Steve.

 

Hi Pat,
Roving is the easiest to spot when you're grinding simply because of the larger size of the weave pattern. If you have enough 1.5oz matt to do the job then roving isn't a bad option and it's considerably less per yard then biax. While it's common for biax to have a matt backing, roving is a less likely candidate for the treatment. I used to use a material called FabMat or ComboMat which was exactly that a Roving/Matt combination. The stuff was a pain to work with in my opinion and hardly worth the effort.

MM