Injecting soft deck areas

[flounderpounder225]

Just thought I would post this up, I have a few areas on my deck that are soft, not real bad but you can feel them.  Just aft and outboard of the console, and midships around the access plates.  So in leiu of ripping the deck out, my neighbor who has been building boats and doing fiberglass work most of his life suggested we inject the coring area in these spots with a slurry of resin and filler.  We used a meat injection syringe without the metal tip, had to drill the spout of the syringe just a little bigger to allow flow, checked the flow ability prior to kicking the resin off.  Drilled several small, about 3/32 holes (the size of the tip) in the area adjacent to each other probably about 6" inches apart, stick the injector in the hole, fill the tube, the insert the plunger and go.  Probably about 3-4 injections in each hole, starts to ooze out the other holes, along with the water it's pushing out .  You can knockmon the deck as it's setting up and hear where the resin has migrated to, it's more solid, and you can feel the deck and it's hot where the resin is cooking off.  Kept wiping the excess as it oozed out of the holes with acetone, small stainless wire brush to clean the non skid pattern out.  Then after it set put a drop of gelcoat in each hole.  I will sand those today.  Got up in her this morning and the area we did is solid as a rock.  I known this is not permanent  fix but will buy me some years, until such time like when the fuel tank may become an issue, or something else.  For time and labor to results, I think it is a viable approach if you just have a few areas of concern.  We have a few more areas to do, so I will trynand get some pics of the process then.

[RickK]

Good deal - maybe we should put this thread in the Resource forum?

[blindmullet]

One other good tip is to start with antifreeze. It kills the fungus that destroyss the wood and allows the epoxy to peneteate better.

[CTsalt12]

Good stuff, thanks for sharing.  What did you use as filler?  I am doing the same thing pretty much, but I scraped out what wood I could using a 90 degree bent screw, and shopvac'ed it.

[96redtoy]

X2 On the filler??

[flounderpounder225]

Silica cabosil thickener, or something very similar for the filler.

[Skoot]

This is really great info.  I've read a lot about the procedure, but nothing about anyone actually completing the task.

Thanks so much for posting, keep us updated.  

[Georgie]

Marc -

I've used this technique a few times and it has always worked wonders for me.  In fact, the first job I ever did (foredeck on my old wellcraft) is 8 years old and still holding strong.  Fiberglass Coatings sells empty white caulk tubes which you can fill with their rot/moisture resistant 2 part epoxy (NOT thickened at all - you want it to spread and penetrate as much as possible, and it must be epoxy, not poly, for the bond strength).  Here's the basic technique I used, but keep in mind it really only works well if the rot is bad enough that the core and fiberglass have delaminated leaving a space for the epoxy to travel through.

1) make sure boat is on mild incline
2) drill series of quarter inch holes in soft section of deck (through the top layer of glass ONLY!) spaced at least 10-12" apart working from the lowest portion of the soft area up the incline to the top of the soft area.  Try to make sure there are no holes on the underside of the deck such as old thru-bolt mounting holes where your injected epoxy can drain out the bottom.  If you find any, seal them with duct tape or similar which can maintain its bond just long enough for the epoxy to cure
3) mix a caulk tube full of epoxy and inject into the lowest hole until you start to see epoxy coming out of the next hole up the incline.
4) plug first and second holes with gray modeling clay.
5) move to third hole up the incline and repeat process every few holes until you've squeezed enough epoxy into the second to last hole that epoxy starts pouring out of the top hole.
6) let epoxy cure fully, then overdrill the 1/4 inch holes slightly (3/8 bit) but try not to drill all the way through the fiberglass layer.
7) remove any residual modeling clay and fill overdrilled holes with slightly thickened gelcoat to match surrounding finish.

For what it's worth, I know NOTHING about the antifreeze trick, but it certainly sounds plausible.  Good luck and let us know how it goes.

Hope that helps.

[jdupree]

Hey Marc.  Did you ever take any pictures of the repair?  I would like to see where you drilled versus the affected area?  I don't have any soft spots, but I think this is a good resource for many.

[flounderpounder225]

Hey Marc.  Did you ever take any pictures of the repair?  I would like to see where you drilled versus the affected area?  I don't have any soft spots, but I think this is a good resource for many.

I will get some pics up soon, basically at the aft end of the center console, going aft to about where the rear legs of the leaning post are (the walking area), almost the same on both sides.  Then in the center, around the access plates for the fuel tank, most of it is under the leaning post, so its fairly inconsequential.

[pzart]

Pics please  :) ....I have a couple large soft spots on my WC, about 8"x16" I would like to try this on, also have a small one on the 170AS that I could use this technique on.

[redemn93]

please post pics.  im very interested as well.  good knowledge for future use.  i would like to try this on my fuel tank cover.

anyone know about th antifreeze?  how long would you have to let the antifreeze sit before beginning the epoxy injections?

[flounderpounder225]

I would only use injection on the deck areas, any hatches and other panels that can be removed are fairly easy to flip over, cut out the old coring and lay in new plywood, and re-glass, permanent fix, pretty easy also.. fuel tank hatches are a common re-core.  Also, Lew SLVRING just pposted some excellent pics on the same thing I did..

[slvrlng]

I finally got tired of stepping into the boat and feeling the soft spot from the console back. The final straw was Bridget climbed in barefoot the other day and said the fateful words "why does the deck feel soft". OK so now is the time before we trailer to the panhandle for the summer. the boat had this soft area when I bought it and I have just been waiting to do something about it. Well today was the day to start the project. I still have lots of resin and cabosil left over so my first step was to figure out exactly where it extended. I laid masking tape around the general area to get an idea of where to start. I talked to Flounderpounder yesterday about some hints since he and his neighbor had just done the same thing on Marc- time.

Tape around area. Most of the soft spot came from the fact that the console was not sealed and the original captains chairs weren't either.

 

Its about 3 feet front to back and about 18 inches wide at the aft end. It narrows up around the console.

Already repaired area where the chairs were and where the cooler seat attaches.


Drilling the first hole. The ply looked good under the glass but once through the glass and top layer of ply there was a void with darker wood.
The farther from the gunwale the darker and more rotted the ply became. Exactly what I expected.

Start with an exploratory hole. The gel was about 1/16, then there was the glass about 3/16, then the ply about 1/2 to 5/8 then a layer of glass under it all. start the first hole very slowly! You will feel each layer as you go through it. I then took some 3/4 tape and wrapped the bit as a guide for the rest of the holes. You want the bit to go all the way to the top of the bottom layer of glass but not through it. Just let it rest on it. Then mark your depth. The tape on the bit worked well until the bit got hot and on the last two holes it slid up the dang thing and I went through. In these holes I mixed up some really thick epoxy and squeezed it into them first and then let it set up so I would have a solid base for the rest.



After figuring out how deep to drill I went on and drilled 14 holes. This was enough to cover about 1 square foot. That was enough for today.



Vacuumed and then taped off with packing tape and masking tape.







3 to 1 medium epoxy. I mixed the epoxy then poured 2/3 into a plastic bowl and added cabosil until it was like peanut butter.







After mixing I got in the boat and pushed the plain epoxy into each hole just to coat everything really well, then filled the syringe with the thickened epoxy and squeezed it into the holes starting at the front and working downhill. (The boat is on the trailer). I kept pushing the thick epoxy into each hole until it started to squeeze out the other ones. I then wiped the excess off and waited for it to cure. So far it seems to have worked . Won't really know until tomorrow.

 



I put the neat epoxy in first to coat all the wood fibers, then put the thickened on top of that. Just checked it and I think its gonna work. I did not step on it yet but the flex is gone when I mash down on it with my hand. Yesterday I could make it flex with my hand.
So , off to drill more holes! I am not going to use the small syringes today, I will use the empty caulking tubes so I don't have to load the syringe as often. That slowed me down a bunch yesterday and boy was it messy!!!!! I don't really care what it looks like in the end just as long as it is strong and doesn't flex anymore!

[slvrlng]

Humidity was way up today with the rain coming so no matter how I tried the packing tape just wouldn't stick. It is nice to rep a making tape line. 62 more holes today, after the 14 yesterday. 3 qts of mixed epoxy and an ounce of cabosil. I realized after drilling about 15 of the holes in the middle of the area that we had been walking on just the glass with nothing but shavings and powdered wood under it.

Started at the edge by the coffin with some really thick stuff because I drilled through in one hole. Let that cure for a while then shot neat resin into all the other holes. Today  also used the caulking gun which made it way faster. Went to the area just below where I worked yesterday and then back down the gunwale side. then to the aft end of the soft spot. Once I had all the outside rim full I started at the bow end and worked my way aft. I would shoot the thickened resin in each hole until it either started squeezing out of the next one or even three holes beside it. As I filled the last section of holes I knew I needed to get it really full to make sure of no voids so I just kept pumping. I pumped enough in that the resin actually bowed the deck up. When I pulled the caulking gun away it squeezed resin out for 30 minutes until it gelled. I then just waited an hour and pulled the tape. I like using this tape. I had very little blow by under the tape.

I think this is going to work and it is already pretty dang solid and it hasn't really kicked all the way yet.



Notice the lack of wood shavings around the four holes, and how dark two of the other ones are.





Hey they want me to test the tape.






Done.