Do I re hydrate hull before new caulking and paint?

[Dave G 9N]

Huh? Did you actually go an watch the video, and see how they just put plastic up to the gunnels?

Yes. They were very good at what they do and they got it to work. Lots of things can go wrong for anyone who tries to repeat the process.

 

[gonzo]

Ethylene glycol swells wood the same way water does. It is very slow to evaporate, will diffuse throughout the wood and will hold some moisture, so the swelling is fairly permanent. Wet it down 2-3 times by spraying with a glycol and water solution, letting it dry between coats.

Ethylene glycol is highly toxic; to people and the environment. It would be insane to soak your boat with it.

 

[Lightfoot]

Ok so glycol sounded like a good option but not if it’s that toxic. steaming is a possibility but logistically hard, is there any reason I can’t hose the hull down and protect it with a tarp and repeat until the hull swells enough(forgive me if that’s a completely stupid question, I’m new to all of this)
Also my original question of what to do first hasn’t been answered as far as I can see? Do I reswell the timbers before caulking? And once rehydrated how do I stop her drying out again? Will paint serve that purpose?

 

[gonzo]

I am used to make a skirt with tarps or plastic from the deck down. Then set a couple of sprinklers to get the hull wet. You can put them on a timer to run a few minutes an hour.

 

[Rumars]

Also my original question of what to do first hasn’t been answered as far as I can see? Do I reswell the timbers before caulking? And once rehydrated how do I stop her drying out again? Will paint serve that purpose?

Sorry about that, I forgot about your thread. Long story short, you can't recaulk a dried out hull that has gaps between planks. The planks need swelling at least enough that you can't see the light of day trough the cracks. To do that, staple some burlap to the hull, install a sprinkler or drip line and cover with some loose plastic so the wind doesn't evaporate all the water. It will take a while until everything swells back, don't expect quick results.

For painting, you wait for the surface to dry before starting. Even so, the best result is usually achieved with a repaint at a second haulout after the wood has completely acclimatized. Best to plan for such a haulout anyway, some seams might need touching up.

Sikaflex for seam compound is a complicated thing, the surfaces need to be completely clean and primed, there is no margin of error from the manufacturers recommendations, or it won't work.

 

[BlueBell]

My question is do I need to re swell the timbers first or afterwards?

Before.

 

[Dave G 9N]

Ethylene glycol is highly toxic; to people and the environment. It would be insane to soak your boat with it.

No, you are mistaken, it is toxic, but not highly toxic. Read and understand the SDS before you pontificate. It is less than half as toxic as table salt. The difference is that you can easily swallow one and not the other. The SDS sheets are linked below.

The EPA rates it as Class III. Toxicity category III is slightly toxic and slightly irritating. It is safe to handle. Just don't drink it or breath it. You should avoid contact, but there is no reason to panic if you get some on your hands while filling your radiator. Mechanics routinely handle this stuff every day. They survive without the kind of lab safety training that I have had, and oddly enough, they seem to survive. I have had to evaluate thousands of materials for hazardous ingredients. I have worked as a chemist for an industrial hygiene group for some little known outfit near Titusville, whose acronym was interpreted as 'never a straight answer', not to mention several major defense contractors. Many hours of safety training.

EG is not exactly toxic, but oxalic acid, the metabolite formed in the liver is toxic. The treatment for ingestion is to drink lots of water and one antidote is alcohol, which ties up the enzymes that break EG down into oxalic acid, giving the kidneys time to flush it out. The orally lethal dose in humans has been reported as approximately 1.4 mL/kg of pure ethylene glycol.[7] That is approximately 224 mL (7.6 oz.) of 50% ethylene glycol for an 80 kg adult and 56 mL (2 oz.) for a 20 kg child.

Ethylene glycol LD50 Oral 7712 mg/kg ( Rat ) That is 7.7 grams.
Sodium choride (table salt) LD50 = 3 g/kg ( Rat ) That is 3000 mg
Ethylene glycol SDS Fischer
Category definitions

 

[gonzo]

No, you are mistaken, it is toxic, but not highly toxic. Read and understand the SDS before you pontificate.

Maybe you should read it. Here is the link to the CDC: Ethylene Glycol: Systemic Agent | NIOSH | CDC https://www.cdc.gov/niosh/ershdb/emergencyresponsecard_29750031.html#:~:text=Ethylene%20glycol%20has%20a%20sweet,Ingesting%20enough%20can%20cause%20death.

It is safe to handle. Just don't drink it or breath it.

How are you going to prevent breathing it after you spray the boat with it?

 

[Dave G 9N]

Maybe you should read it. Here is the link to the CDC: Ethylene Glycol: Systemic Agent | NIOSH | CDC https://www.cdc.gov/niosh/ershdb/emergencyresponsecard_29750031.html#:~:text=Ethylene%20glycol%20has%20a%20sweet,Ingesting%20enough%20can%20cause%20death.


How are you going to prevent breathing it after you spray the boat with it?

Sigh, again, read and try to understand the SDS. The STEL, 50 ppm, can be avoided with reasonable ventilation because the vapor pressure is very low.

From the EG SDS:
Vapor pressure; 0.12 mm Hg at 20°C. Vapor density; 2.14 (Air = 1.0)
Water has a vapor pressure of 17.5 mm Hg at 20°C. The density, you can do the math, MW of H2O is 18, CH2OHCH2OH is 67.
That should be enough to tell you that short of breathing a fine mist, you are unlikely to encounter any difficulties. Perhaps I should have said to avoid using a fine spray in a confined space, but that seemed unlikely. After spraying it, which is the question you asked, you would be hard pressed to breath enough to worry about. While spraying it, you need to exercise reasonable caution, but it's not as bad as when spraying a lot of paints.

Nothing in your CDC link is inconsistent with what I said. You need to have read a few of these things to know when to panic. In your own link did you look at the
NFPA 704 SIGNAL

• Health: 1
• Flammability: 1
• Reactivity: 0
• Special:

Ratings of 1 mean slightly hazardous. You need to pay more attention to the 3s and 4s. NFPA 704 - Wikipedia https://en.wikipedia.org/wiki/NFPA_704

EDIT:
Mea culpa.
Wikipedia is unworthy of our erudite industrial hygiene guru.
Understanding the NFPA 704 Diamond Labeling System | Creative Safety Supply https://www.creativesafetysupply.com/articles/understanding-nfpa704labelingsystem/
1 – Level one for the health hazard category is for any chemical that will only cause mild irritation or injury due to exposure. In most situations, no extra personal protective equipment is needed beyond perhaps gloves.
1 – Any material or chemical that will burn, but only when heated significantly. These materials must have a flash point of 200°F or higher.

 

[gonzo]

This is a quote from the CDC, which is more credible than Wikipedia or your paraphrasing:
Early ethylene glycol intoxication is like ethanol intoxication but there is no odor of alcohol on the patient/victim’s breath. Initial adverse health effects caused by ethylene glycol intoxication include:

• central nervous system depression,
• intoxication,
• euphoria,
• stupor, and
• respiratory depression.
• Nausea and vomiting may occur as a result of gastrointestinal irritation.
• Severe toxicity may result in coma, loss of reflexes, seizures (uncommon), and irritation of the tissues lining the brain.

The toxic metabolic by-products of ethylene glycol metabolism cause a build-up of acid in the blood. This process is called metabolic acidosis. These toxic substances also affect the cardiopulmonary system and can cause renal failure. Metabolic acidosis commonly occurs after ethylene glycol intoxication, but absence of acidosis does not exclude ethylene glycol toxicity. Serum ethylene glycol levels do not correlate well with clinical presentation.
Untreated ethylene glycol poisoning can be fatal.

 

[Dave G 9N]

This is a quote from the CDC, which is more credible than Wikipedia or your paraphrasing:

OK, You win. You can follow me around and make specious arguments until I give up. Anyone who thinks multi speed transmissions are reasonable to expect on a 1950 era 6 hp open utility is not someone to argue with.

 

[gonzo]

OK, You win. You can follow me around and make specious arguments until I give up. Anyone who thinks multi speed transmissions are reasonable to expect on a 1950 era 6 hp open utility is not someone to argue with.

I said than any small gearbox can be mounted to it. Please don't misquote me. I have done hundreds of installations; many of them with adapters.

 

[sdowney717]

Yes, you should not caulk such a dried out hull.
I have been rethinking the whole plank caulk procedure lately and wondering why not do something entirely different, and a lot easier.
Such as use the canned polyurethane closed cell spray foam insulation or the spray foam construction adhesive, both are waterproof, both have adhesive qualities, they would go a long way in seam filling for a low price.

Simply the idea is, you dont want hard caulking in planks where the seams are wide open, such pounded caulking is for the wedge effect, with planks tight at their base next to a frame. Planks swell edges get tight, caulking seals up the imperfection between edges. But it can also be caulked too tight.

Use the closed cell spray foam in a can, right into wide open seams. Stuff is soft enough to not cause a problem when planks swell up to each other. The leak is sealed likely permanently as the spray foam will stretch again on another haul out. And the spray foam has adhesive qualities, a lot stronger than you might think. In the US, it is called Great Stuff, gaps and cracks up to 1" and I have experience using
GREAT STUFF 12 oz. Gaps and Cracks Insulating Spray Foam Sealant 227112 - The Home Depot

the construction spray foam, I am not as familiar with but it this here in the video.
GREAT STUFF CONSTRUCTION ADHESIVE (youtube.com)

 

[sdowney717]

All these old boats when new had tight planked seams with a small bevel cut into one plank edge for hammer driven cotton thread caulking.
Over the years the planks edges compress and wear, the gaps get bigger and bigger until the boat needs hull work to fix the planks. The degradation process is inevitable, simply caulking when boat is out of the water, and then it goes back in, the planks swell against the new tightened caulking and the edges wear some more. It especially wears the caulking bevel worse so that gets bigger. I am thinking that spray foam will slow down that from happening. The spray foam will seal the planks and allow the planks to swell and seal against each other without the boat leaking or sinking when going back in the water. Planks will still swell with less restraint on their edges compressing them down and there will be less strain on the fasteners.

And you should forget about using toilet bowl wax rings, I tried those 20 years ago and nearly sank. I said never again. With the various methods I have done, I go in and do not get any incoming water even after long haul outs.
I have always verified the current coating and or resealed the outer planks with another polyurethane coating paint after that near sinking.

 

[Tomsboatshed]

Ethylene glycol is highly toxic; to people and the environment. It would be insane to soak your boat with it.

For those who may be interested: the best synopsis I’ve seen on the toxicity of ethylene glycol.
HEALTH EFFECTS - Toxicological Profile for Ethylene Glycol - NCBI Bookshelf https://www.ncbi.nlm.nih.gov/books/NBK600985/