# Injecting epoxy in wet core



## Guidera48 (Jan 7, 2009)

As I prepare to tackle the dreaded soft side deck repair, I am doing research on how to go about it. It seems this repair falls into 2 options. Drill and fill on small areas or cut and recore, on larger areas.

How about this. Any one tried it??

Drill several holes around the damaged area. Install a 1/4 air male hose fitting in the middle of the area. Attach a hose and vacum pump. Leave sucking at low pressure and remove the moisture. Later on, intruduce thinned epoxy into the holes and draw it accross the area. Close the holes one by one as epoxy comes out of the vaccum pipe. 

Will air pass through the damaged area? Water already has.

I have read many posts describing injection of epoxy with seringes,however they all rely on gravity and wicking to move the epoxy across the damaged area. 

A little help from a vacumm system surely would help draw and saturate the core faster. Is there such a system??

O.K. Let me have it.

Thanks


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## camaraderie (May 22, 2002)

I've actually had this done on a boat of mine...on a drill and inject under pressure until the epoxy comes out the other hole(s) basis. It ONLY works on very small areas and is not a suitable approach for repairs to more than a few square inches. 
If you have larger areas of softness/wet core/delam...the only option is a complete removal of the laminate and core replacement.


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## joethecobbler (Apr 10, 2007)

injecting the epoxy or resin sounds like it would work. 
My concern would be the water / moisture removal to in preparation for the repair.
I've found exopy cures differently with alot of moisture present, like rain or soggy wood.


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## Capnblu (Mar 17, 2006)

Perfect type of repair for a de-lamination, but misses the point entirely for a rotten/ wet core. It won't work, sorry, all you will do is make a bigger mess to fix. If you are comfortable with vacuum bagging, tackle this repair from below, thickened epoxy to bond the new core to the underside of the deck, then use 3m 77 to hold the glass layers in place, 2 sets of hands will help. Set up your bag, and infuse. I use an old pressure cooker with an extra line plumbed in for the infusion line, then add air pressure to the cooker to aid in epoxy transfer. I also would use extra slow hardener, and consider chilling if the area is large. I think MAS has epoxy specifically for this, But I like the West personally. (old habits die hard) good luck


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## camaraderie (May 22, 2002)

CBlu... to be clear...I agree with you entirely...it is a temp solution suitable for stabilizing a very small area and the right way to do it is your way. Sometimes a quick fix is suitable from a a time and $$ standpoint...but it is not a cure.


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## TSOJOURNER (Dec 16, 1999)

*I vac. bagged my keel*

it was full of water and diesel and did injections it works , wanna see pics ???


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## jarcher (Jul 29, 2008)

GREGGWARREN said:


> it was full of water and diesel and did injections it works , wanna see pics ???


Yes, please!


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## Capnblu (Mar 17, 2006)

If your keel was full of water, and diesel, you did nothing. epoxy does not adhere to either. Of course this is my opinion, please prove me wrong.


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## slippery (Jul 29, 2009)

*Core repair*

technicalyy this repair method could be very dodgy! why...

1. you have to ensure the core material is dry to a level of less than 5% "active water" throughout the entire 'damp area" and that the core material is not compromised.

Injecting Low viscosity Resinsinto holes does not gaurantee you get resin to all the soft or "compromised areas of foam! NOR ITS POOR ADHESION WITH THE FIBREGLASS OUTER LAYER.

Using a vacum pump combined with direct heat will drive out water but if salt water has been present you will leave salts (sodium) behind and thus the epoxy's adhesion will be compromised. Also fungal growth with fresh water could cause similar problems.

You will also need to moisture probe (electronic)the core between holes to ensure no trapped water.

2. Injection of a low viscosity epoxy into the holes will not ensure total "gap filling" and will no resurrect the strength of the original lay up. Also the holes could be possible areas for further water ingress if not filled and sealed correctly.

Also, low viscosity epoxys do not like high film builds!

3. Cutting out the effected area (from one side only, typically the underside ) and replacing the core using a angled cut of 8:1 for the foam joints followed be re instatement of the fibreglass using a tapered / feathered edge tehnique (12:1)is best and will maintain integrity of deck.

4. The only technology that could be injected into a hole or used in contact with moisture would be a moisture cured Urethane but the above still applies.

And.. if your idea worked every boat builder (worth his salt) all over the planet would be doing it and i don't believe they are
Hope this helps


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## TSOJOURNER (Dec 16, 1999)

So how big is the area you are repairing? Would it be possible to just cut/router out this area and replace with marine ply (or whatever core material) and epoxy it in place?


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## mitiempo (Sep 19, 2008)

How big is the wet area? In my opinion, if you cannot remove all the wet core easily through a single small access hole then you're better off to cut open and recore it properly. The other problem with your plan is that if it doesn't work, and I think the consensus is that it won't, you have caused whoever does the future recore job (you) a great deal of work removing the skin to do it properly. Recoring is very hard to do properly from below and very messy. Vacuum bagging will help but still not necessarily a guarantee of successful bonding. The best way to a successful job is to do it from the top. While this means repair to deck coating - painting or non skid - it will also go much faster depending on the size of the wet area to be recored.
Brian


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## KindOfBlue (Nov 22, 2005)

I recently went through this. I considered all options and after people pounded in "get rid of the bad", I decided to recore the area. I'm glad that I did because now I know that its solid.

After carefully marking off, cutting and removing the top skin from the damaged area, I realized that the damage was larger and I had to keep cutting. I think that its typical to find that the damaged area is about 15% larger than you thought. 

Good luck.


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## CharlieCobra (May 23, 2006)

It's best to re-core because CPES does NOT displace water. The core has to be totally dry to use epoxy on it.


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## Tom Wetsel (Jun 16, 2017)

I injected with 35 cc syring and large needle I cut short. I drilled with a tooth pick sized bit. i injected three times wih day cure between each. You could tell by drilling if voild. Some holes took 35 cc. More than 10 ounces would set before injected. Some would come out other holes
I made. sure all 60 holes about 1.5 inch apart were filled. Sand and painted. i am sure it strong enough. Solid no give.


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## travlin-easy (Dec 24, 2010)

I had a 3 X 6 foot area drilled and filled, the wood beneath was not rotted, though, just wet. A shop vac was used to dry things out, and nearly a gallon of epoxy was injected in the holes, then the holes were sealed, gelcoated and painted. There is absolutely no wet in there at all now, and the water was coming in from around the base of the mast boot, which looked good on visual inspection, but you could follow the water using a moisture meter. 

I can assure you that my deck is now more rugged that it was originally and though it had been wet it never got soft and soggy like some that had been overlooked for decades. Once you get the wood dried out, and the epoxy injected, there is little chance it will ever rot. Balsa is a fairly soft, but resilient wood and not prone to rotting as some would like to believe.

Good luck,

Gary


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## gamayun (Aug 20, 2009)

I was just talking about this the other day with a friend. I was told (with no verification about this info), that if you use fast cure epoxy, you're likely to burn the boat down with the heat build up. Best to use slow cure and maybe do it on a cool day...


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## eko_eko (Sep 7, 2012)

You're not supposed to thin West System epoxy to make it penetrate. It will just weaken the epoxy. Use heat instead.

Thinning WEST SYSTEM epoxy - Sailfeed


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## JamesRichy (Feb 25, 2018)

Clearly replacing the core is the best option, but often is not logical in an older boat used for coastal cruising, where the cost of the repair could easily exceed the value of the boat. It's a lot of work, make no mistake. I have done the job and my repair is in an issue of Good Old Boat in 2004. I wouldn't do it again. First, why return an ancient deck to as new condition? Have you seen decks fail? In my 45 years of being around boats, I've never seen one failed deck. So ask yourself "what am I trying to achieve here"? 
If the core is not rotten epoxy injection is good. Very expensive yards use this as the method of choice, including Morris Yachts. It makes zero sense to rip out sound core to replace with more sound core. (Although many will happily charge you thousands of dollars to do just this). Acetone can be injected periodically until it's dry. Or you can use Boatlife Aquapoxy which cures well in wet wood. Size of the repair does not matter. Then inject unthickened epoxy. Do not thin it. If the deck core is rotten, you might consider injectadeck, which is a 2 part structural marine foam that remains liquid for the first 30 seconds or so, and penetrates into any cracks, crevices or gaps. It is attracted to moisture, and cures better in the presence of moisture. It then expands, and cures rock hard. Of course, you might get some small voids, but the deck I have seen repaired with this method is absolutely rock hard. Another approach might be the one taken by Aeromarine Industries, (see their video on deck repair). They inject structural foam between the overhead liner and deck, then epoxy into the dry deck core. This looks massively strong. If the core was wet and rotten, I'd use injectadeck into the core or Aquapoxy, but definitely not regular epoxy. None of these methods are perfect, but they do work, and can keep your boat going safely for many, many years. They are also about 1% of the work of replacing the core. Replacing the core would be an absolute last resort for me, and only if I planned to use the boat in extreme offshore conditions.


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## SloopJonB (Jun 6, 2011)

I've done both - drill & fill falls into the same category as painting a rusty car before selling it.

You can vacuum out the liquid water but everything is still wet. It just plain doesn't work.


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## JamesRichy (Feb 25, 2018)

Well, a painted rusty car will show the rust again in a few weeks. There are epoxy injected decks going strong after 20 years. Hardly the same thing. Yours may have failed, but it can and does work in many cases. As I mentioned, it is used by excellent yards and recommended in certain cases by the Goudgeon Bros. Take some wet, rotten wood. Put it in a plastic or aluminum tray. Pour aquapoxy over it, until covered. In a day or two, you will have rotten wood encapsulated in rock hard epoxy. I'm not saying it's a good as replacing the deck. Far from it. But it definitely does often work, it adds structural rigidity, lasts a long time, and makes the most sense for may boats. Of course, a quick and dirty job probably will fail.
Like blister repair, many self-proclaimed experts will advise you on repairs far, far in excess of what is warranted or logical.


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## Tanski (May 28, 2015)

I recored about 16 square feet with 1/2" endgrain balsa.
Didn't think it was an expensive or difficult job compared to other boat jobs. In fact just the opposite, was pretty cheap and easy. Hell cost me more for two batteries and a new smart charger for them.
Not saying it isn't a bit messy and lots of sanding filler but it isn't actually difficult, unless you failed cut and paste in kindergarden....


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## mitiempo (Sep 19, 2008)

If you inject epoxy into core that is wet it will cure. It will stick to dry areas but not wet areas. It will make a proper repair by the next owner a nightmare.


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## Maine Sail (Jan 6, 2003)

mitiempo said:


> If you inject epoxy into core that is wet it will cure. It will stick to dry areas but not wet areas. It will make a proper repair by the next owner a nightmare.


Dug into "Band-Aid" repairs far too many times. Very, very frustrating..

There are no miracle cures to repairing wet decks, that I've torn into yet, that are worth much of anything other than to make the _correct repair_ a complete nightmare.

Products such as those mentioned above in this thread, eg: expanding PU foams etc., are relatively new and yet remain unproven over the long haul. Most of them lack structural testing data or _cut-a-ways_ showing it to actually do what the marketing claims it will. There are thousands of hurricane damaged boats with wet-decks that can be injected then cut open to see how these products actually work but I've searched high and low and these tests, and cut-a-ways, don't exist that I've found.

As a marine professional I would welcome such a product but so far every method I've seen tried, other than cutting the deck open and re-building it, has failed to do what it claimed it could. They only made future repairs a bigger nightmare.

Perhaps someone has a link to some structural third party testing data and cut-a-way images of repaired wet decks using some of these products?


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## mstern (May 26, 2002)

mitiempo said:


> If you inject epoxy into core that is wet it will cure. It will stick to dry areas but not wet areas. It will make a proper repair by the next owner a nightmare.


I've got deck delamination in my 1979 Oday 23. I've considered both recoring the deck and using one of the "injection" methods to fix things. So far, I've done nothing, mostly due to the fact that I can't see the repair making a big structural difference, especially given that I am a fair weather daysailer for the most part. One thing that has never entered into my calculation is how an injection-style repair would impact future owners. I can't see how anyone would ever think that recoring the deck on my boat would be a good idea. The cost of new core material, epoxy, glass cloth, filler and paint would far exceed the value of the boat.

However, I've never heard of Boatlife Aquapoxy; maybe I'll check that out!


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## mitiempo (Sep 19, 2008)

mstern said:


> ........The cost of new core material, epoxy, glass cloth, filler and paint would far exceed the value of the boat.


The materials needed are not that expensive - it is mostly labor intensive.


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## afraidofsharks (Jan 17, 2018)

mstern said:


> I've got deck delamination in my 1979 Oday 23. I've considered both recoring the deck and using one of the "injection" methods to fix things. So far, I've done nothing, mostly due to the fact that I can't see the repair making a big structural difference, especially given that I am a fair weather daysailer for the most part. One thing that has never entered into my calculation is how an injection-style repair would impact future owners. I can't see how anyone would ever think that recoring the deck on my boat would be a good idea. The cost of new core material, epoxy, glass cloth, filler and paint would far exceed the value of the boat...


Haha. I did this on an Oday 23-2; 1978. It's where I stand to step the 100000 pound mast and it was going to keep getting worse. I do sail offshore (well coastal) and just want the thing solid and watertight. I'd do it again if I was going to keep the boat for 3+ years and was ok with an imperfect looking deck.

What are you guys spending all your money on? It cost about $300 give or take. I think $45 for the coring, and 150 or 200 for tte epoxy, of which I used 2/3rds. Fairing was 20? Mat was $15. Then gelcoat.

It was not really that difficult...mainly waiting for the core around the edges and the winter rain to dry. The difficult part since I did it from the top (couldn't fathom cutting out the bottom and figuring out how to make glue soak upwards away from gravity's pull) is how to match the yellowed fiberglass + texture with the new gelcoat. Keep in mind it looked a bit better when I cleaned the rest of the boat to match the newer color, cleaning off all the dark dirt surrounding the fixed area (which I did tint a bit yellow and a smidge black - actually a very close match).

The deck is solid enough to dance on now. As long as I keep up with basic through hull maintenance it will never have to be touched or worried about again. I just don't want a boat with mushy decks ready to cave in. Crackling decks annoy me too.


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## mstern (May 26, 2002)

afraidofsharks said:


> Haha. I did this on an Oday 23-2; 1978. It's where I stand to step the 100000 pound mast and it was going to keep getting worse. I do sail offshore (well coastal) and just want the thing solid and watertight. I'd do it again if I was going to keep the boat for 3+ years and was ok with an imperfect looking deck.
> 
> What are you guys spending all your money on? It cost about $300 give or take. I think $45 for the coring, and 150 or 200 for tte epoxy, of which I used 2/3rds. Fairing was 20? Mat was $15. Then gelcoat.
> 
> ...


I think I have the skills to do the work, just not the time or the place. Even if I did find a place and the time to do the work, I figure that a lot of the cost would be in making things look right after recoring the deck. I have been calculating that I'd have to repaint the entire deck and coach roof to have a consistent color. I'm not particularly finicky, but I don't think I'd be happy with big patches of a different color on the deck. Forget about costs completely if I had the yard do it.....


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## gaffcat (Nov 17, 2016)

The previous owner of my boat repaired some soft spots on the deck with Gorilla Glue. Gorilla glue cures with water. He injected the glue into several holes drilled in the areas. The directions for the glue say to wipe both surfaces with water before spreading glue. The areas he repaired seem sound with no indication of softness.


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