And so it begins
- Thread starter 25yearslater
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Hey guys, just back from an overnight down to Baltimore. Youngest son is going to summer school again at a little college there called Johns Hopkins University. So now that I'm back the restoration continues. In this whole process some differences are worth noting. Jibes brings up a good point about wood cores. One benefit to all this is the bonding and wet out of the balsa core. The balsa is essentially plasticized when bonded with the epoxy from the bottom and subsequently saturated during the glass layup. It is virtually turned into a chunk of plastic wood. Another benefit is the cloth and epoxy form a watertight capsule for the balsa. The final step was the barrier coats applied over the fairing compound which was also epoxy. The gelcoat then becomes strictly cosmetic and need not offer any protection other than shield the epoxy from the effects of the ultraviolet light. Any weight penalty gained by plasticizing the balsa is more than offset by the Knytex fiber density and the reduction in epoxy in the composite structure. So it may not be necessary to resort to high cost core materials, but time will tell.
When talking about saturation of the balsa, how deep into the wood do you think the epoxy will soak? I'm sure viscosity has a lot to do with it. I have epoxied lots of plywood and found that the epoxy does not saturate very deep at all. I'm sure the glue layers act as a barrier but even on the end grain it doesn't soak in very far. I still think it is a lousy method of construction and think boat builders should go back to solid wood. Then you can see it rot right before your eyes instead of hidden where you can't see it.
Well it's time to chime in again. Wet cores.... lots to discuss.
How deep will epoxy penetrate? without solvent.. nearly nothing. With solvent... allot. CPES brand (Clear Penetrating Epoxy Sealer) say's it can penetrate 9 inches. Jibes is probably right about he glue stopping the penetration. CPES is over reduced epoxy and not much more regardless of what they claim. Over reducing the epoxy leaves it very weak and sponge like. Thats OK for cores. (better than being water logged)
For large areas , I agree with Joe. Cut it open but I have been able to repair cores in small areas without cutting them open.
First step is to ignore everything they say at CPES (Smith and Company) they are just trying to convince consumers that their product is much more that over reduced Epoxy. The MSDS says differently. Check out http://www.epoxyproducts.com/penetrating4u.html to make your own penetrating sealer.
Second step identify all areas that appear to be de-laminated. They will likely have deck cracks and soft mushy decks. Use the tapping method to find out how large they are.
Next go over your entire deck using the tapping method. Circle the areas that you did not notice previously with a permanent black magic marker and within each circle write in large bond letters "DON'T TAP HERE !!!" this will prevent anyone from noticing that these areas are wet or decontaminated. You can now focus you efforts were they will make a difference. The areas with the deck cracks and or mushy spots.
My point here is that moister in core is not a terrible thing in itself it's the deck cracks and mush spots that are the problem. The O'day 40s all have cored hulls and all have soggy cores yet most are still going strong. You can easily tell the difference between an O'day 40 (cored Hull) from a O'day 39 (solid core) since most 40's have a sign that says "No Hull tapping allowed".
Again.. use Joe's method on large areas. Try the drying method on smaller areas.
This website is as good as any for directions. http://www.cncphotoalbum.com/doityourself/rotrepair/rotrepair.htm
One word of caution: if your are replacing core DO NOT follow their recommendation to teat the new core with CPES prior to gluing it in place. The bond will fail since the CPES is very weak. It will be too weak for the epoxy to bond well to it. Joe's right, the core will be protected well enough when you do the layup. Keep in mind that the rest of your boat has no CPES in the core.
The acetone is the key to the process. I recommend repeating it three or four times prior to adding the penetrating epoxy.
My O'day 22's cores were all soaked and de-laminated. I used the drying method on 1/2 of them and worked well. I must admit that the strength may be in the solid filled holes spaced evenly throughout the repair not the balsa core which I'm sure has moister in it.
How deep will epoxy penetrate? without solvent.. nearly nothing. With solvent... allot. CPES brand (Clear Penetrating Epoxy Sealer) say's it can penetrate 9 inches. Jibes is probably right about he glue stopping the penetration. CPES is over reduced epoxy and not much more regardless of what they claim. Over reducing the epoxy leaves it very weak and sponge like. Thats OK for cores. (better than being water logged)
For large areas , I agree with Joe. Cut it open but I have been able to repair cores in small areas without cutting them open.
First step is to ignore everything they say at CPES (Smith and Company) they are just trying to convince consumers that their product is much more that over reduced Epoxy. The MSDS says differently. Check out http://www.epoxyproducts.com/penetrating4u.html to make your own penetrating sealer.
Second step identify all areas that appear to be de-laminated. They will likely have deck cracks and soft mushy decks. Use the tapping method to find out how large they are.
Next go over your entire deck using the tapping method. Circle the areas that you did not notice previously with a permanent black magic marker and within each circle write in large bond letters "DON'T TAP HERE !!!" this will prevent anyone from noticing that these areas are wet or decontaminated. You can now focus you efforts were they will make a difference. The areas with the deck cracks and or mushy spots.
My point here is that moister in core is not a terrible thing in itself it's the deck cracks and mush spots that are the problem. The O'day 40s all have cored hulls and all have soggy cores yet most are still going strong. You can easily tell the difference between an O'day 40 (cored Hull) from a O'day 39 (solid core) since most 40's have a sign that says "No Hull tapping allowed".
Again.. use Joe's method on large areas. Try the drying method on smaller areas.
This website is as good as any for directions. http://www.cncphotoalbum.com/doityourself/rotrepair/rotrepair.htm
One word of caution: if your are replacing core DO NOT follow their recommendation to teat the new core with CPES prior to gluing it in place. The bond will fail since the CPES is very weak. It will be too weak for the epoxy to bond well to it. Joe's right, the core will be protected well enough when you do the layup. Keep in mind that the rest of your boat has no CPES in the core.
The acetone is the key to the process. I recommend repeating it three or four times prior to adding the penetrating epoxy.
My O'day 22's cores were all soaked and de-laminated. I used the drying method on 1/2 of them and worked well. I must admit that the strength may be in the solid filled holes spaced evenly throughout the repair not the balsa core which I'm sure has moister in it.
Hi jibes and panta rei. I am curious at this point to see how far West Systems will penetrate end grain balsa without thinning. Jibes makes a good point about why are they using wood. My best guess would be cost. In a production situation pennies per square inch add up fast. If I were a money no object person I would have chosen one of the premanufactured honeycomb deals that are the standard on high end racing craft. You're right about moisture and wood Todd. All wood reaches equilibrium with the ambient humidity. My house of logs is a perfect example. In the summer the logs swell and the house becomes tighter. In the dry of the winter the moisture level drops and things loosen up. Interior walls shift from season to season which requires compensation to keep doors from sticking or being impossible to latch. The biggest problem as I see it is when the core is saturated such as mine was. In a southern enviornment this may not be as serious as those of us in the northern climates. That intense freezing in the winter is what causes the worst of the delamination. The trapped water turns to ice and with no room to expand it makes for a formidable wedge. The other problem I observed was repeated moisture caused the growth of fungus which actually disintigrated the balsa. Dark stains on the cabin liner where the remants leeched in were the warning signs. I have encountered a substantial amount of dry core as I moved forward and the starboard foredeck seems to sound out in fine shape. I'll replace the cloth here anyway as I have concerns about introducing asymetric loads via the differences in cloth selection. As I said I will run a test on some balsa and see if I can come up with a way to determine the penetration depth of using epoxy in it's unthinned state.
This is the way Epoxy products made their test. Seems simple enough. I hope I did not scare you away from penetrating epoxy. It may be rubbery but hardness is not required in a core. Just don't treat wood (balsa core or other) with Perpetrating epoxy before bonding something to it or it to something else.
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Hey Todd. That's interesting how they are immersing the wood in epoxy. The osmosis is carrying it up the grain much like the water in the core. I personally am not using penetrating epoxy but following the West Systems Manual with regards to core bonding. They do offer a way to improve penetration by suggesting warming the epoxy to lower it's viscosity. When following up with glass cloth it must be sanded to form a good mechanical bond since the chemical bond is no longer possible. What I'm finding truly amazing is how well built the Oday line truly is. This boat was being sailed with all the defects I have posted until I bought it. How the rig didn't go over the side is a mystery but is also a testament to it's durability.
You pointed out the major flaw in the concept of drying and saturating the core by drilling holes in the deck sandwich. Water wicks out and epoxy wicks in with the grain not across it. Nothing is going to penetrate very far across the grain. Again, I think the true strength of drilling and filling are the holes filled with epoxy. The core surrounding the holes likely does little.
As for penetrating the new core, I agree temperature will thin the epoxy and improve penetration but heating epoxy is touchy. It would be terrible if it kicked over just as you were applying it. A lot of time and material down the drain.
As for O'days, I think they are the best deal out their. I purchased the 39 for 1/10 the cost of a new boat. It too was sailing when I purchased it. I came across a O'day 40 in Chicago. It had massive de-lamination in the hull. It sold before I had a chance to make and offer. I wanted to talk to the new owner about his project boat. I was surprised that he had no intention of repairing it. He intended to re-bed a few items and go sailing. He paid $28,000 for a 40 foot boat and planned to sail it for 5 more years and eventually sell it to one of us for about the same price. Pretty cheap sailing!!
No one did finite element analysis on these designs. They likely sailed the first one out of the mold and watched for stress cracks and added re-reinforcement as needed.
We have a tremendous advantage over the engineers that originally designed the boats. We have deck cracks that point to areas in need of re-enforcement. No analysis needed just read the cracks.
As for penetrating the new core, I agree temperature will thin the epoxy and improve penetration but heating epoxy is touchy. It would be terrible if it kicked over just as you were applying it. A lot of time and material down the drain.
As for O'days, I think they are the best deal out their. I purchased the 39 for 1/10 the cost of a new boat. It too was sailing when I purchased it. I came across a O'day 40 in Chicago. It had massive de-lamination in the hull. It sold before I had a chance to make and offer. I wanted to talk to the new owner about his project boat. I was surprised that he had no intention of repairing it. He intended to re-bed a few items and go sailing. He paid $28,000 for a 40 foot boat and planned to sail it for 5 more years and eventually sell it to one of us for about the same price. Pretty cheap sailing!!
No one did finite element analysis on these designs. They likely sailed the first one out of the mold and watched for stress cracks and added re-reinforcement as needed.
We have a tremendous advantage over the engineers that originally designed the boats. We have deck cracks that point to areas in need of re-enforcement. No analysis needed just read the cracks.
Hello Ruidh,
I used plywood in place of balsa core and all the wrong adhesives when I rebuilt my O'day 22 and it's holding up great. Maybe we are all over thinking this stuff.
I got the information from the wooden boat forum. They do not seam to like the product. http://forum.woodenboat.com/showthread.php?52046-CPES-The-Cure-or-Just-Snake-Oil Here is a quote concerning it's sealing ability.
Quote:It shows where after an application of four coats of CPES, there was still an moisture absorption rate of 33% by weight compared to a rate of 7% when CPES was used in combination with standard epoxy and 3% to epoxy alone!
In this web site he states "the water uptake of timber treated with "penetrating" epoxy is about 5 times that of the Modern Epoxy"
In my own conversations with representatives from WEST, System 3 and Progressive Epoxy Polymers it appears far better to apply a lightly thinned initial coat of epoxy End Quote
It looks like Joe is heading the right direction.
I used plywood in place of balsa core and all the wrong adhesives when I rebuilt my O'day 22 and it's holding up great. Maybe we are all over thinking this stuff.
I got the information from the wooden boat forum. They do not seam to like the product. http://forum.woodenboat.com/showthread.php?52046-CPES-The-Cure-or-Just-Snake-Oil Here is a quote concerning it's sealing ability.
Quote:It shows where after an application of four coats of CPES, there was still an moisture absorption rate of 33% by weight compared to a rate of 7% when CPES was used in combination with standard epoxy and 3% to epoxy alone!
In this web site he states "the water uptake of timber treated with "penetrating" epoxy is about 5 times that of the Modern Epoxy"
In my own conversations with representatives from WEST, System 3 and Progressive Epoxy Polymers it appears far better to apply a lightly thinned initial coat of epoxy End Quote
It looks like Joe is heading the right direction.
The whole reason to drill all the little holes and inject epoxy is because the deck is delaminated, so you aren't trying to go through the grain, you are trying to force an epoxy mixture to flow through the delaminated region to cause it to rebond or fill in all the mushy wet areas and harden. I also doubt the effectiveness of this method, mixing epoxy with a bunch of rotten wet wood does not sound like a good practice.
Jibes, you make a great point. The only way anything is going to penetrate balsa is from the end grain. But these guys are talking differently. Both say to drill into the core.
http://www.star-distributing.com/howtoguides/corerestoration.html
http://www.cncphotoalbum.com/doityourself/rotrepair/rotrepair.htm
I have a few smaller areas were I'll try the drill holes, pour goop, and pray method but will remove the skin on more serious problems.
One thing I do know that works is flushing with Acetone. I used it on the o'day 22 on core that was soaked but not rotted. It truly did dry the core. As for CPES, I'm beginning to think it's best used on soft spots in Joe's log home. After all that is what it was originally formulated for.
I'll now shut up now and give Joe back his thread. Head over to the wood boat forum if anyone wants to read more on the CPES controversy. Quite a hot button issue.
http://www.star-distributing.com/howtoguides/corerestoration.html
http://www.cncphotoalbum.com/doityourself/rotrepair/rotrepair.htm
I have a few smaller areas were I'll try the drill holes, pour goop, and pray method but will remove the skin on more serious problems.
One thing I do know that works is flushing with Acetone. I used it on the o'day 22 on core that was soaked but not rotted. It truly did dry the core. As for CPES, I'm beginning to think it's best used on soft spots in Joe's log home. After all that is what it was originally formulated for.
I'll now shut up now and give Joe back his thread. Head over to the wood boat forum if anyone wants to read more on the CPES controversy. Quite a hot button issue.
I'm enjoying this conversation. So for tonight I'll just post some befores and afters as my low shrink gelcoat hasn't arrived so I headed for the cabin. Don't know why I didn't pop a picture of the bulkhead with radio/cassette player, hole for back of compass and some crazy auxilliary electrical panel that had no apparent purpose except to cover a gaping hole.
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You should get a dashboard from an airplane as a replacement and use it to cover the gaping hole. It will be a great converstation piece.
I had a delaminated rudder and drilled millions of little holes, injected acetone and let it dry for a while. Then I injected WEST system epoxy, clamped it all up and hoped for the best. It stayed bonded for several years until I decided to get a new rudder. I was worried the structural steel inside was compromised from the water ingress.
I had a delaminated rudder and drilled millions of little holes, injected acetone and let it dry for a while. Then I injected WEST system epoxy, clamped it all up and hoped for the best. It stayed bonded for several years until I decided to get a new rudder. I was worried the structural steel inside was compromised from the water ingress.
Damn, why didn't I think of that. Combine my love of sailing with flying. Just think, an attitude indicator instead of an inclinometer, I could tell pitch and roll at the same time. I did get pics of that bulkehead so I edited the previous post, they were back on page 3.
Hey 25,
A gaping hole in a boat can be a real problem. Especially if the gaping hole is on the bottom of the boat. On the other hand, the hatch is a pretty big gaping hole too. At this point in your adventure I would recommend you get one of those artists from the 70's that painted up the volkswagon microbuses for the hippies and have them decorate Yot for you.
A gaping hole in a boat can be a real problem. Especially if the gaping hole is on the bottom of the boat. On the other hand, the hatch is a pretty big gaping hole too. At this point in your adventure I would recommend you get one of those artists from the 70's that painted up the volkswagon microbuses for the hippies and have them decorate Yot for you.
Standby for a major announcement about restoring nonskid deck patterns. Pictures and details this evening. It can be done!
:dance:Well the eighth time was the charm. While not perfect only the most minor flaws are present and would be undetectable to a casual observer. So how'd I do it? With this pattern being so delicate a new mold was poured as the old one had reached it's limit after six attempts. This time instead of cutting and stretching the screen it was rolled across the partially cured urethane. This eliminated any preshrink tendency in the mold. Next, the formula. 9 ounces #10214 low shrink gelcoat brush consistency colored in this case to light gray. This is available from Advance Coatings Company. This is a no wax gelcoat. Next, 4 ounces Duratek High Gloss Additive. 1/2 tsp MEKP catalyst. Spray a base coat of the colored gelcoat on the area to be imprinted as a separate step. Make sure the color is even across the entire surface. Coat the mold with Pol-Ease 2300 lightly and allow to dry. When the gelcoat is slightly tacky like weak tape lay waxed paper onto the area. Position the mold and SECURELY tape one end. Roll the mold back to the tape and remove the waxed paper. At this point I LIGHTLY wiped the surface with acetone and rag to remove any wax. Do this lightly and quickly as the gelcoat will soften. Mix the gelcoat and Duratek and then add the MEKP. Mix thoroughly. Fill squeezy bottle and apply a generous amount at the juncture of mold and deck to clear the air from this area. Begin to unroll the mold and keep a generous wave of gelcoat advancing in front of the mold. This is a messy process so be forewarned. When the mold is fully down begin using the LONG spreader to squeeze out the excess gelcoat from under the mold. Vary the direction to keep the gelcoat thin and the mold flat. This is where I encountered the bump problem in previous tries. A small spreader merely moves the lump around under the mold. Gelcoat should be seen oozing from under the mold and to the ground below. Make sure the edges stay down to prevent gaps. After 12 hours the mold can be rolled back and you too can enjoy your original nonskid deck.
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Deja vu! YOT stripped of the deck outer skin and core starboard side. This is strangely familiar.
