Digging in the deck

[Stephan]

I've decided to try a unconventional way of fixing some wet spots in my deck. I wanted to avoid weakening my deck too much, so I thought instead of totally detaching the top FG layer, I'd drill out some big holes and poke the wood out from there:

65926593

Indeed the balsa was totally wet and had mostly detached from the fiberglass. My next steps will be to remove the wood below the rims of the holes, maybe with a wire brush attachment for my Dremel or drill, dry it some more, and then fill it all with epoxy. Maybe try to thread some pieces of FG in there, too. I'd cap it with the round deck pieces I saved, fill the gaps, and fair it.

What do you think?

[Tony G]

I recall a recore job being done by cutting discs in the top skin. The author numbered all the holes and discs. If I recall correctly, Good Old Boat featured the article in one of their issues. I bet if you contacted Karen Larson she could give you the issue number.

[bill@ariel231]

the holesaw method will work too but with all the patching of the deck, you may find it more time consuming than reaching for the circular saw to remove the top skin... at least that has been my approach for A-231 and other boats. The downside of the circular saw method is you will want to remove all hardware from the deck, and the project may quickly turn into a complete deck recore (not hard, just time consuming).

Nothing wrong with patching the bad spots and getting back out there this season. good luck! :)

[carl291]

It appears in the photos that the core is bad in an area where there is no deck hardware. This would lead me to think that this entire deck area is bad. If I were to make the type of repair your doing just to get back to sailing I would use balsa to go back in your holes and not all epoxy. My reason would be that this area will have to repaired in the future and I would not want to grind all that epoxy out at a later date. The balsa grinds away a lot quicker and is a quicker and cheaper filler material. Just a thought.

[mbd]

I remember that GOB article. It was done with a much smaller hole saw though.

To add to Carl's post - if you don't address where the water is getting into the core and to keep it from getting in in the first place, fill the holes with core-cell of another closed cell foam products so you won't be repeating the same repair a few years down the road.

You may also want to take a normal drill bit and drill exploratory holes out from a bad area until you get to good balsa just to "map out" the areas you'll need to address and to get an idea of how extensive a repair you have on your hands. It would also give you an idea of where the water is getting in. It goes without saying to be sure not to drill all the way through the inner skin...

[Tony G]

Stephan,

Bill, Carl and Mike are right. You don't want to put a whole lot of effort and money into it if you are just going to tear it all out and do it over again in the near future. Using a smaller drill bit and 'mapping out' the wet spots is a very sound and good idea. If you can accertian where the water is getting in, you could address the ingress. Then if the decks are not delaminated too significantly, you could recore the areas most important for strength and safety (chain plate penetration, load carrying hardware, stantion bases) and with a little planning leave the larger, open deck areas to be recored after the sailing season.

Having said that, the safety of the captain and crew is most important followed by assuring the ship is sound enough to get out and sail. And of course, pictures help.

[ebb]

There have been other thread(s) on this subject in this Forum.

I agree that the holesaw/disk method will preserve the camber and integrity of the deck. But I also agree with bill that if you have extensive rot cutting out panels of deck will prove easier. However that depends on your inner skin of the composite. If it is as thin as is is on LittleGull you may have a problem keeping integrity when you work on it scraping off the rotten balsa.
IE you may have to support the inner skin from the inside if you remove large pieces of foredeck.

HOWEVER, it is evident from the photos that to get good results you will have to remove all fittings from the deck. I agree with numbering and mapping each and every disk removed. While the making of the deck unit by Pearson required some precision in the construct of the composite/sandwich there could be anomolies that would not allow interchanging the disks, even if they are all cut with the same holesaw.
For instance when you drill closer to the toerail or the cabin you will find that the core peters out and becomes solid frp.

The balsa core on LittleGull is 3/8", however I did not have to redo the deck. So my suggestions are practical ones. If you continue with the disk method you might be able to pass a router over the hole to clean out the rot. I would probably screw on a slightly longer plate on the router made out of acrylic (so you can see the work better) and span the holes easier. You can ofcourse scrape them out - but a straight bit will give you an exact cleanout without messing with the inner skin.
Since you will be putting back in the holes a 3/8" disk of divinylcell (med density pvc closed cell foam - my recommendation) have a clean hole makes many clean holes easier to do. This foam is 'structural' foam. Whereas endgrain balsa which is also a good choiuce if you are replacing with lots of well buttered epoxy. Still the pvc foam can be tailored to a hole very easily, the foam will take a feathered edge and will marry just as well if not better than balsa with the hole.
Get plain, not scored, foam. Make your disks from the foam with the same holesaw.
Bosch makes a quick change holesaw system that make it easier to push the disk out from the blade.
But you can make a guide block out of dense ply or board by running the holesaw through it. Then position the block where you want a hole and cut in without the centering drill bit. The foam will take poking better than the endgrain balsa.

I would undercut or clean out a 1/4" or so around the rim of the hole so that the epoxy goop and foam disk will never want to pop out. You will want to dry as much as possible with a heatgun, hair-drier or a heater, etc the core in the areas you are not disking. Pushing the exhaust from a hot vacuum cleaner into the holes would work good too imco.
I think it a better idea to leave tunafish in the hole to soak up epoxy that you will be injecting into these areas thru smaller holes after you have finished the disk repair stage.*
If you have water in the tunafish you might drill some holes up into the core from inside to drain. Of course you can't do this on the side decks of an Ariel. But you should make a valiant attempt to dry the remaining core.
Make sure the returned disk is at the level of the original deck - not above. Orientating marks are made with a pencil before you remove the disk. Three swipes with the pencil across the cut, they'll be different on each disk, and you will have number each disk so that the skin is put back orientated exactly where it came from.

I'm going to assume you've run into Ebb's rant on using epoxy on old polyester to get the best bond.
I won't recommend West System epoxies. You want to use 100% solids, no solvent, laminating epoxy as your base. Use fumed silica as your thickener and milled or cut glass to add strength to your goop where you need it.

You might mark where stanchions are going and instead of putting a wood insert/core just build it up solid with Xmat (epoxy friendly mat) and cloth.
After you have sanded the deck and probably removed most of the original gelcoat and anti-skid you may want to tie together your new plugged deck with a single layer of fiberglass cloth over everything you've done.

OK, No Problem
Good luck
__________________________________________________ __________________________________________________ ____
*Smith's CPES system may have been upgraded for core repair. But I would NOT inject water-thin CPES into the remaining rot areas. The stuff does not set up hard, which is what you want. You want to inject laminating epoxy into the skin. Laminating epoxy is made to wet stuff out. If you have dry/semi dry tunafish the epoxy will soak in and you'll end up with something hard. If you have no tunafish in places, you can inject a loose mix of epoxy and aerocil that will buildup in the hole with a syringe It's not perfect but if you're careful the deck will last another 50 years!:cool:

[commanderpete]

The traditional re-core method would be the best way. Otherwise, some alternative method would be common practice.

But, I think you have a workable plan. It looks like you have access to the whole sidedeck from the dics holes you've cut.

You can get a thin wheel attachment for the drill and rout out the old balsa as far in as it will reach between the skins. Something like this (8 inch size)(if it's thin enough):

http://www.jamestowndistributors.com/userportal/show_product.do?pid=54854&familyName=3M+Scotch-Brite+Clean+and+Strip+Disc#

To get in deeper, you could stick a long drill bit in between the skins using a right angle drill or attachment.

Maybe even make your own wire drill attachment: cut lengths of wire and bundle them together into a brush. Put the bundled end of the wire brush into the drill chuck.

Wrap an acetone soaked rag around the brush to finish preparing the surface.

Squirt thickened epoxy in there. Then soak cloth sheets in thickened epoxy and jam them in as far as they will go.

A few air gaps won't matter. The fiberglass will make a corrugated core between the skins and it will be immensely strong.

For the disc holes you've cut, You might want to use balsa or other core material there.

The scraps from cutting the core material, and other fiberglass mish-mash, can be shoved between the skins.

I would also do one or both of the stantion bases shown in your pics, without core.

[Stephan]

Guys,

thank you all so much for your advice and the time you spent writing your responses. This is the reason why I love this group and want to remain a member, in spite of having a stretch ariel.
I'm going to go over each response a little more tomorrow, but I can clarify a few things now:
1. The wet area is limited to the area where I put those four holes and a few inches further. There's another soft area on the foredeck, but I won't tackle it yet, it's not really that bad. If I had to remove more of the deck I'd indeed use the 'traditional' method of cutting the upper skin off.
2. The area I drilled open is right at the entrance gate in my lifelines. People keep stepping on there, and I had some mold just below there in cracks in the inner liner, clearly fed by this moisture.
3. You can see that the PO had attempted a repair of this area many years ago. The deck under the stanchion bases is filled in with epoxy it seems. The bases are rock solid. However, you can see a rectangular crack where the repair was done. This is in my opinion the place where water seeped in. There is no other source I can think of. I think the repairer did not chamfer this area and so the crack developed.
4. The balsa core is indeed apparently just 3/8 in thick. It appears, from looking at the disks, uniformly thick, so the disks are probably interchangeable if I cannot figure out anymore which is which. I hope.

As promised I will write more tomorrow.
I had ordered MAS epoxy and slow hardener from Defender, but they didn't send me the hardener yet. I was planning to increase the strength of the cut areas by using epoxy instead of balsa, since I didn't expect the discs themselves to be able to add much strength.

Stephan

[ebb]

Tried to scare up the guy who disked his whole deck.
I think it was a Triton or a stretch Ariel.
He is an ER doc and I wondered at the time what techniques he used in his Emergency.
Actually the disk method of access and repair for small areas of rot is perfect. Almost anything is going to work well - including filling the holes with glass.
I will argue that replacing the tunafish with disks of pvc foam is almost as structural and strong as solid glass - and you'll be using less epoxy.
Imco, after you have restored the disk areas you might drill holes into the remaining rot areas and inject straight epoxy. Or drill in slightly larger holes thru the deck to inject in epoxy gel mixture. This will erase the hollow sound when you tap the deck. The syringe is a two ounce model and some frp suppliers now carry them*. It makes it ridiculously easy to get gelled epoxy into tight areas, for instance under the rim of a disk excavation where you have removed sodden balsa. Imco.

The injection technique might also be seen as creating a dam in the core to stop water migration.
It also is a good idea to remove your thru-deck fastenings sometime and give them the epoxy treatment. Because 99.99% of all deckrot comes from unsealed holes in the deck. imco
__________________________________________________ _____________________________________________
*TAP Plastics syringe applicator

[Tony G]

It very well may have been Mark Parker, MD. The hull number evades me at this time but she was a Triton named All Ways. Mark planted the idea of wood toerails in my mind. I think he did teak decks on her with plastic composite faux teak. It was a shame they never posted larger pics of All Ways on any site I've found. He spends some time down in Belize near Punta Gorda and Placencia sailing cats now, if I recall correctly. Sorry for the sidebar-I gotta strike while the iron is hot with this mind.
********************
Yup. It was Mr. Parker. We've discussed him here before regarding those 'trex' decks. Oh yeah, it is Triton 516...

[Stephan]

Jesus, that looks scary. If I had that much deck to recore, I'd really do the 'cut it all off' route.

[Stephan]

Well, one thing I didn't realize when I started this hole digging idea was that the deck has a much stronger outward tilt than I imagined. So today when I mixed the epoxy I added, as you had suggested, the balsa chips I had extracted to try to make the epoxy more viscous. That didn't really have much of an effect, unfortunately.
I had taped off the boundaries, fortunately, so the overspill that resulted was limited, however, I ended up having the inboard (upper) disks not totally immersed in epoxy, while the outward ones were overflowing.
I feared disaster, but after an hour of curing time I could pull off the tape and get most of the overspill off. I added a smaller batch of epoxy later to try to fill the inboard gaps, but I will have to repeat that exercise in a few days because there are still more gaps.
Next I'll have to fair the area and repaint, with a bit of anti skid (sand or something), too.
I didn't take photos of this stage, it's looking a bit embarrassing, actually, but when the next batch is on I will

[ebb]

I'm flaberglassted. Have to reread your post in the morning.

[Stephan]

Ebb, is it so confusingly written? I did choose the route of pouring epoxy only, and not to add new core. I didn't make that explicit indeed.
I think next time (I hope there won't be next time) I'd choose the traditional method. The hole method doesn't allow the introduction of new core, and grinding out the old core is much harder and not as complete when you have to go through the holes. Nevertheless the wirebrush disk did work pretty good and allowed me to get most of the old wood out. The rest was sufficiently dried.

[ebb]

Ayedunknow. Can see how many find my words eye-glazers.
I wouldn't have poured in plain epoxy to try to fill the holes.

I would have cut disks of Xmatt and/or fiberglass cloth and laid them in stacked like pancakes and then capped the stack with the well buttered disk of skin.

the butter is epoxy mixed with Cabosil or alternative. The butter can be strengthened with chopped strand, which is usually 1/4" fiberglass pieces you buy by the pound or jar.

I would have prepared the holes by scrapping out the rotted balsa (with a Bacho tri-angle carbide scraper) and discarding the stuff.
I would then excavate slightly under the rim of each hole.
I would then have inserted a disk of pvc foam.
But as an alternative I could build up the required 3/8" with rounds of Fiberglass.
I would have made sure those rounds were saturate with liquid epoxy.
I would have finished each hole replacing the disk of skin that was originally removed with the holesaw.
Because the liquid epoxy can find its way into a rotted core I would have stuffed chopped strand strengthened epoxy gel into any visible space.
There may have been caves in the balsa around the rim of each hole. I would have pushed epoxy gel with chopped strand into them. I then would have laid in the rounds of fabric or pvc and capped with the disk of skin.

After the holes were filled and hard I would tap the parts of the rotted deck that were not disked out with the holesaw. If I found hollows (dull sound) I would drill in3/8" holes into them and inject them with liquid epoxy. If the liquid epoxy did not top off, I would inject epoxy gel into the drill holes until no more goes in.

Would continue this drill and fill process until no more epoxy goes in and there are no more dull hollow sounds when tapped.

Pouring in liquid epoxy into a space in an attempt to fill the space is not considered a good idea.
If the space is large and the epoxy is there in large quantity the exothemal reaction can get very hot. The area around the epoxy can get distorted, even burn, and the epoxy will boil, get frothy, and become useless..

Imco the solid epoxy fill you have does not compromise the small area you worked on. Laminating epoxy, being very thin, is formulated to be used with fiberglass and other fabrics. It also makes great fillets and installation gel when mixed with fillers like fumed silica, glass and plastic spheres and milled glass. The epoxy in itself is brittle when set and really needs to be married with the stuff it is designed for.

If you had wet out your holes with liquid epoxy -
then filled the required interstice with epoxy gel (in place of where epoxy saturated glass rounds OR pvc would have gone -
Then capped with the original top skin disk WELL BUTTERED WITH EPOXY GEL.. that could have flown.



EPOXY GEL
You need Part A and Part B epoxy to mix together. It should be the best epoxy available.
You need fumed silica to mix into the Part A - Part B mixture.
You make your liquid and fold in the Cabocil until it starts thickening.
You control the thickness with how much of the powder you mix in.
It can be quite thin but still have some body to it - or very thick and very stiff. There is a happy medium.

Epoxy blended with fumed silica is stronger than plain epoxy.
If you need extra strength: to this gell you add milled fiberglass pieces.
You can add too much and get a hairy goop. You use this stuff to give the epoxy gel some GRAIN (as in wood grain), some structure - because plain hard epoxy is brittle.
And plain hard gelled epoxy, while very strong, gets much stronger with the addition of a little 1/4" chopped strand. It becomes 'structural'. And nearly impossible to break - or to sand - so don't build it up.

[I have learned it 's easier to fill mild hollows and imperfections with easy to sand fairing compound. The one West System product I can recommend is their 407 fairing filler which you mix with your (NOT West System's) laminating epoxy to produce a chocolate colored surface you can sand. You can use this stuff under the waterline. There is another material: 410, but this compound should be used inside only.]

You can't inject epoxy gel that has chopped strand in it. The gell will be adequate in the core repair. Inject it to fill hollows. It also will naturally fill all your drill holes.

Making gel allows you to fill tilted decks, vertical walls and holes overhead like in your liner in the boat.

Damp balsa doesn't make a good thickener. Any pieces of ANY material (even glass micro-spheres you can use to make fairing compound with) when mixed into epoxy liquid will fall out. It'll sag. You need a matrix like Cabosi to make a gell to hold added materials like balsa in suspension.
You need the Cabosil to make a filler that won't move before it can set. You need the Cabosil in your fiberglass kit. Liquid epoxy is generally only used to wet out laminations of fabric.*
If you want to make a glue as for plywood, or backing blocks, or fillets you have to add the fumed silica.

This still doesn't read CLEAR, but I really hope it is useful.
__________________________________________________ __________________________________________________ _______
*Laminating epoxy makes a great sealer and grain filler for mahogany that will be finished bright.

[Stephan]

Ebb,

you should have do it for me! :D I knew that polyester resin by itself is useless and needs glass mat, but with epoxy I wasn't aware of that. I had also considered that no matter what, the epoxy would be stronger than just new core. The heat factor didn't seem to be as bad as you described, because I used medium hardener which took a good time to kick and didn't develop that much heat. It was pretty warm, but not hot enough to cause brittleness or worse.
I had considered somehow threading mat into the holes and beyond, but thought in the end that the mat would make it more likely I'd get air bubbles and that the epoxy wouldn't flow into all the crevices. The balsa chips (almost dust really) were dry at least.
The gap between the upper and lower FG layer is filled now and the disks are in place. I don't know if I will find somehow that the deck is not sound now - if I find it cracking of course I know I screwed up badly and will have to really remove the mess I made.

Thanks everyone for their advice, especially you, Ebb. If my job is terribly botched it will serve at least as advice how NOT to repair the deck!

[ebb]

I don't think you've botched it.
There are a hundred ways to fix this problem.
You may have invented a perfectly decent method.
I'm an Opinionated Old Fool, glued in my ways.

Epoxy is very forgiving stuff.

Good luck to Stretch
and great sailing!!!:cool:

[c_amos]

If you would like to hear it, I think I have a 'compromise' fix that might work out.....

....like ebb (our OB1 epoxy guru) said, epoxy is forgiving and it may work out ok.


If you want to be more sure, you could take a router, set the bit to a little over 3/4" (or what ever seems appropriate from your core samples, and the material you used. I would not aim to bottom it out in each hole, just get near the bottom.... Might use something like the Dewalt Rotary tool as a router, so you can get much closer to the cabin top and the rail then a regular router would allow....

I would remove the stanchion and include the raised area in your repair, it looks like someone did some kind of repair there in the past...


The idea is you want to remove any 'stress points' where the repair ends, or at least spread them over a larger area.

Route the area all down.. deck and all, just outside the area of your repair.

Once you have a larger area, you will have 'milled down' these 'resin rich' repair areas. Then you can build the entire area back up with layers of epoxy and fiberglass.... fair it all back in, and you should have no worries about it in the future.

[ebb]

Hey Craig, that's a goodun.
For close to the toerail stanchion excavating using a 1/2" router,
you have to jig the router up to toerail height and maybe box it in to control it.
Excavation would be done with a long 1/2" straight bit that you'd lower in small increments to determine the depth you want. A bit dangerous, I think.
You could say that you are incorporating the backup pad into the upgrade.
But I think greater thickness translates to less likelihood of bending the fastenings that hold the stanchion.
Also getting a better no leak seal.

I have a Bosch 1HP router called the Colt (about the size of a malt licquor can.)
It accepts 1/4" shank bits. With an alternative base you could excavate as close as 1 3/8" from the toerail right ON the deck. This may be close enough as I think this area, on the Ariel deck anyway, is solid frp. Anything you can't get with the mini-router you can with a Dremel.

This small router in this ap, with careful lowering of the bit, can be freehanded, I think, into the deck. Two handed control. Sharpie pen the limits with a nice rounded perimeter and excavate to the depth you want. If you are lucky enough to have 1/4" deck skin and 3/8" core, I wouldn't go deeper than 1/2". Whatever depth...I'd work cautiously down to it.
In imagining about this, I think that if there is a little balsa/polyester stuff at the bottom of the excavation I would incorporate into the frp pad you are upgrading with. Not willing to cut through the flimsy inner skin.
A big plus is filling in the old wore out stanchion fastener holes and starting fresh!

There might be rot around the foredeck vent that this method would do well with.
There is certain to be a little rot under the mast. This might do well there as well.
Very well, thank you:D

[Stephan]

I hear you. I dread redoing it immediately, I want to get on the water asap! But sure, nothing is lost for good, just time and materials wasted. I'll finish this off now and will keep an eye on whether it develops stress cracks or not.

[Stephan]

The PO stated that the paint used on deck is Awlgrip, 'powder blue'. Unfortunately it appears that Awlgrip has dropped that particular color! Does anyone know of powder blue, and if any other blue comes close? Would be silly to have different blues on deck, and it will be a pain to do little repairs to the topsides paint (which does need some touching up indeed)

[ebb]

Sky Blue come close?
Maybe call an Awlgrip tech and ask which of their 15 whites you might add to which blue to get the old color. Maybe they just changed the name.
Or experiment:
Sometimes you can find one ounce touch up jars of color and white for sale. You know, so you don't have to buy $80 quarts.
Keep a record of your mix. Get a dozen graduated 100ml (3 oz) plastic measuring cups to play with.


Hmmmmm....yas...ahhh...
let's see,

20ml of SkyBlue plus 5ml of CloudWhite equals PowderBlue.
Maybe 5ml more white... Voila!
Close enough.

Once you know the proportion you can always reproduce any quantity tomorrow.
Until they change the base colors again.

[Stephan]

Tried to call Awlgrip tech support, there's some kind of mess with their telephone numbers, basically I can't find anybody so far.
But I'll keep trying. Your idea with the touchup bottles is nice, although they charge $20 for each, so that's another $40 for a few ounces of paint. Bloody expensive stuff, I could get 4 liters of Bacardi for the same money.

[mbd]

Allocate your funds properly and you won't care what color your decks are. ;)

[carl291]

Stephan, You did read about thickening (?) the epoxy to where it has the consistency of a cake frosting or some say peanut butter? Silica , cotton mill fiber, etc. etc. as a thickening agent.

[Stephan]

Carl, I added a lot of the 'sawdust' from the excavation. I didn't want it to be too viscous, to encourage it to flow into all the open spaces, so I didn't achieve that cake-frosting feel. I was worried too that I was running out of time. Unfortunately, that meant it was too thin to not seep out from the lower areas. I guess I should have realized I can't have it both ways.
However, I think that this will be just a nuisance to fill the not completely filled gaps. I hope that it's structurally sound, else I have a real mess.

[ebb]

The only epoxy I know that is "viscous" is 'structural epoxy'.
It is thick epoxy you get when you want to glue things together like wood.
You cannot use this stuff for deck or deck/core repair.

For that you must have very runny 'laminating epoxy' - which is like warm maple syrup, not viscous.
The only thing you can use to thicken that stuff is fumed silica. (Aerosil, Cabosil)
With that you can make infinite 'gels' - ranging from flowing to stand-up stiff.
None of these gel mixes that you make with epoxy liquid and fumed silica are viscous in any way.

This NOT opinion, OK?
If you mix any other material into runny epoxy, no matter how thick it seems to get, it will not stay stiff. It will move. The only exception is cotton flock. And most proprietary powdered products like West SDystem's 407 and 410. Which have fumed silica as part of the ingredients.

If you mix balsa bits into the correct epoxy liquid for core repair ie: laminating epoxy, the resulting peanut butter will not be stable.
This may be what you want.
You may want the mix to wet out its leading edge. It maybe that there is enough surface friction in the hole you are filling to hold the mix.
But as the mix heats up in exotherm it will loose its body and sag.
That is what happens, OK?
If you want balsa bits or any other material like micro spheres to wood flour to fiberglass fibers you have to include fumed silica in you ingredients. Otherwise it'll move before it sets.

This will not happen if you make your filler with enough fumed silica.
Enough fumed silica: you probably have to mix up fillers a number of times to find out for yourself.
EG, enough fumed silica in a fillet mix (this means a stand alone gel mix you'd use to form inside corners in fiberglass work) could be described as 'medium peaks', as if you were beating up eggwhites for a recipe. When you lift the mixing stick out of your goop, the peaks will just fall over at their peaks. But of course the material has more body than beaten eggwhites - this metaphor only describes the look of your fumed silica/epoxy mix.
In one sense this mix is relatively 'dry' - you can scoop up gobs of it like egg whites - it leaves no trails - not viscous.

If you are mixing up gel to stuff into excavated holes under the deck, you can make the material much looser. It will fill such narrow spaces better if it is looser.
But you don't want it runny because then it will not fill the space and stay in place.

If you want the work you are doing to marry with the repair you should
FIRST wet out the area you are stuffing or laminating with laminating epoxy liquid. Then you mop up the liquid with towels until the surface or hole is damp but not running with liquid epoxy.
Then
SECOND you butter your filler into or onto whatever you're doing.
Leave this step out at your peril.

There is no 'viscous' to this. Except for your hands and tools you can do this work with your best suit on. Viscous is polysulfide and most of the other tube rubbers and two-part rubbers that create long strings of material and are messy in the extreme.

See post #16 for 'epoxy gel'.
Look, if you don't trust crazy ole ebb, then get yourself a book or pamphlet on the subject.

[Stephan]

Ebb,

I'm a total noob when it comes to epoxy, and I'm glad you giving me all those tips and set me straight. I really don't doubt you are 100% right. Unfortunately I thought this saw dust would be just good enough - and you were proven right indeed. I didn't understand the difference between 'viscous' and 'thick', or used the words wrongly.
The MAS epoxy and hardener is very 'thin' indeed, and the saw dust didn't change that much. I didn't pay attention to your tips to use fumed silica, forgive my ignorance.
Anyways, the stuff is in, it didn't burn or warp anything, and unless it cracks, I hope I didn't do serious damage. If I did, I have to get a big fat grinder and remove some or all and glass it properly, as you suggested all along. But I'm desperate to get into the water, with the season in Chicago being short enough as it is.
On top of it I have still numerous other projects, including finishing the fridge insulation and new inner liner. Since I have to work my 5 days a week, that doesn't leave me much time...

[carl291]

Fiberglass and epoxy is very forgiving to work with, while at the same time being a fast learn with a little guidance. I have no doubt that you did no further damage or weakening of the deck. Nothing is weaker than wet tuna fish balsa which is what you had. Carry on.

[Stephan]

I hope so. But even if Epoxy is forgiving, Ebb is not! ;)

[Tony G]

Allocate your funds properly and you won't care what color your decks are. ;)
Great discussion on epoxy technique, but, I just thought we should give Mike's post it's due recognition.

[Stephan]

Very true indeed. Mike, your suggestion is well received. Pardon me if I don't follow your instructions while using my router though.

[mbd]

You may also want to keep your used epoxy container around for a day or so to verify the mixture has hardened.

[SkipperJer]

Stephan, your decks are way stronger than they were before. The strength of a cored deck comes from the fact that the balsa core keeps the top and bottom skins tied to each other when stress is applied. By maintaining their parallel alignment and not allowing them to skew sideways in relationship to each other as upward or downward pressure is applied, the deck becomes much stiffer with little extra weight. It's the I-beam principle executed in fiberglass instead of steel. Almost anything that keeps the top and bottom skin in alignment and water out will duplicate the original strength. You've surpassed that by tying them together with epoxy. Replacing balsa with epoxy adds a lot of weight over large areas but it looks like that is a minor issue for your repair. GO SAILING!