What sealant to use?

A

Ashley Lynn

New member
FIrst off let me apologize, as I know this topic has been discussed----searched and browsed the Hull, Deck, Fittings forum and did not find what I was seeking.

I want to reseal the area in the cockpit, where the cockpit floor meets the cabin wall. The original sealant looks to be deteriorating and I want to reseal it.

I know others have resealed this area and I even remember pictures. WHat would be the best product to used?

Thanks C-brats,
 
I have been using 3M 4000 fast cure, UV resistant sealant recently. It has the properties of 4200 as far as adhesion, but does not yellow or deteriorate as the 4200 does. I would think that this seam would be ideal for this sealant.
 
My recollection is that earlier boats had this area glassed in. I assume that you have the floor boards which can be removed? In my 2006 boat I believe it is glassed--now I'll have to check in the am.
 
I pulled the floor boards this AM-and the aft bulkhead to the hull is tabbed in with glass--looks like one layer of 6 oz cloth. Did not check the inside.

Do you have a photo of where the sealant is? The 25's had a sealant between the aft deck and bulkhead.
 
I think 2007 may be the first year of the permanent/flat cockpit sole, so perhaps it's the joint between that and the after cabin bulkhead that needs to be re-sealed? (I don't know how that joint is made.)
 
Still C-razy is a 2007 and has the permanent sole. The junction between the forward part of the cockpit sole, and the aft cabin bulkhead appear to be a sealant, not glassed. And, mine has a few little places where there is some minor cracking in the sealant. I'll be watching this thread. I don't think there is much hurry on doing anything with mine.
 
I just acquired a 2007 and I have the same issue between the aft, outer bulkhead of the cabin and the forward cockpit sole - the sealant is cracked in some places and looks a little mildew filled. I will be watching this thread as well.

To me, it looks like some of the sealant used is the same stuff that the boat is lined with on the inside of the cabin - it is that speckled stuff. Does anyone know what the structural design of this permanent floor piece is? If water is able to find its way through the cracked seal in the cockpit floor, will it sit inside the floor, or beneath it? The cockpit floor on mine seems to be glassed and gel-coated to the bilge area, so any water in there seems like it would be trapped.

Simon
 
OK,
The floor boards in my 2006 are in two pieces, and can be pulled up to clean underneath. I suspect that in 2007, they put either one piece or the two pieces together, and then ran a bead of sealant around the perimeter of the floor. The actual joint between the hull and the aft bulkhead will be below the floor, and will be glassed as in my boat--and boats before floor boards.

I prefer to have the floor boards removable, so I can clean out under them. However there are advantages to having the floorboards "glued" in place.

Go with the 4000 for the sealant between the floorboards and the aft bulkhead. You want to clean out any old caulk, use a solvent and even scrap of sand the old sealant.
 
Thanks everyone>

My 2007 has the "permanent raised floor", I will dig out the old sealant and use the 4000 as Dr Bob suggests.

I also want to replace my aging size 24 Dual-purpose Exide Nautalus batteries and am thinking about Dual purpose AGM's one in each Lazarette. Any recommendations on brands, which size will fit in the stock Lazarettes?

One last question, I want to replace the file line that goes from the input of the external water/fuel separator to the internal fuel filter of my Suzuki 115, went to WM and their stock 1/4" line does not match, the internal opening is smaller on the WM hose. Question is, is the 1/4" unique to the motor manufacturer (Suzuki) or is it that WM just didn't have what I needed?

Thanks again....I truly do appreciate the wealth of knowledge of the Cbrats.
 
Regarding batteries, there are lots of opinions many of which, I suspect, have merit; my experience is: I started with AGM Optima Blue tops for both starting and house, the initial set lasted and performed very well. But..when I replaced them, a year or two ago, the new ones failed quickly. I was told by a reliable source that Optima had been bought out and the new batteries did not meet the old standards. I have switched to Interstate and Costco group 24 batteries for my house batteries, even going away from AGM to regular sealed batteries. They have worked fine but there are advantages to the AGM batteries relating to ability to be heavily discharged and recover, plus, should you wish to, you can install them on their sides.
 
My understanding is that the Group 24 is what will "easily" fit in the lazarette. I have my batteries between the fuel tanks, and now that the lazarette is sealed up, I can use it for dry storage.

Generally the AGM are best used for several purposes: That is inside the cabin because of less/minimal gassing, if the batteries are difficult to access and electrolyte level is difficult to access and add, or if the batteries have to be place on sides or ends (not upside down) to make them fit in place. The AGM are much more expensive, and don't particularly last much longer than a high quality lead acid battery. AGM will take a charge more rapidly than a lead acid, but with the outboard engines, and alternator output for two batteries that is probably not a factor. Also the self discharge of the AGM is less.

More debatable is the life span if deeply discharged. All batteries will do better if not discharged more than 50%--12.2 resting volts. Some web sites claim that the AMG battery will not be harmed (much) if it is discharged to 80%--while others say that the life expectancy in cycles will be compromised as in the lead acid if deeply discharged regularly. Also when we are "cruising" it is rare that we charge the batteries back to 100%--that is done in the 3rd stage of a charger with long low voltage charging. Usually we get to 80-85 % charge.

I only use the AGM for in the cabin or unusual position applications. If you have 5 years out of the original batteries--that is good, and I would tend to stick with that.

Be sure and get all of the old sealant out of the groove. Use a scraper, and then lacquer thinner, with one of the scotch pads to clean the groove. Use masking tape to control the edge of the sealant.
 
Another word of caution about AGM's. Make sure your outboard's alternator output is compatible with the charging requirements of your batteries. Don't ask me how I know this, :x , but Yamaha alternators may ruin your AGMs. At least the lower HP (below 150?) Yamaha alternators are not sufficiently regulated for AGMs, which cannot handle a charging system that operates at 14.8 volts, or more.
 
Generally AGM's will handle the outboard charging systems. It is the GEL cells with cannot tolerate voltages more than 14.1 volts.

Here is the quote from Yahama web site:
"VRLA batteries – AGM and Gel-cell – are particularly sensitive to overcharging; therefore, use a good constant potential, temperature-compensated, voltage-regulated charger.

Never use a constant current charger on VRLA batteries."

There is another post on the Yahama owner's forum:
"I spoke with Yamaha Customer Service earlier today and posed the
question regarding AGM batteries. The technician told me that Yamaha's
primary concern regarding "maintenance free" or sealed batteries is
related to "Gel Cell" batteries. It is due to the charging voltage
required by Gel Cells. He went on to explain that the charging regulator
on the F250 Yamaha 4 stroke puts out 14.5 volts - this is precisely
what the AGM batteries require - which happens to be the same voltage
which is recommended for standard lead acid (flooded) batteries.
The technician was very knowledgable and politely listened to my question
and concerns. He answered my questions and explained that the
charging voltage was the issue (with Gel Cells) but did not present a problem
with the newer AGM batteries as they very closely mirror the same
charging requirements as standard lead acid flooded batteries.

The customer service number for Yamaha, in Kennesaw Ga., is
(866) 894-1626. "

Finally there are many boaters who have used AGM's with Yahamas with no problem--so you can make your own choice.
 
While I will defer to almost anyone on this subject, especially Dr Bob, I do know that my first set of flooded batteries lasted 4 + years, and the AGMs lasted a year. I also know that my Yamaha gauges show my Yamaha engines charging the batteries at 14.6 to 14.8 volts regularly. YMMV.
 
JUst a word to be cautious about the OEM gauges we use for our outboards. They are notoriously off in my experience over the last 15 years. I always carry a digital voltmeter that I can trust, and check gauges on each new boat or motor install. That allows me to mentally tweak what I'm seeing on the gauges and have a more realistic view of what is being indicated on the gauge. If gauges are right on the money great. I've not done the digital voltage meter checks on my new to me twin Suzies, but as I'm replacing the 6 year old batteries this year, I'll be making my own calibration table up for the analog "in dash" meters.
 
potter water":2ftneajj said:
JUst a word to be cautious about the OEM gauges we use for our outboards. They are notoriously off in my experience over the last 15 years. I always carry a digital voltmeter that I can trust, and check gauges on each new boat or motor install. That allows me to mentally tweak what I'm seeing on the gauges and have a more realistic view of what is being indicated on the gauge. If gauges are right on the money great. I've not done the digital voltage meter checks on my new to me twin Suzies, but as I'm replacing the 6 year old batteries this year, I'll be making my own calibration table up for the analog "in dash" meters.
Click to expand...

My Yamaha gauges are digital. Two engines and two gauges. I also have a Xantrex Link 10 Monitor for the house battery, and BEP VSR to isolate the two banks. Although the starboard Yami gauge will sometimes show slightly lower charging voltage than the port side - e.g., 14.6 versus 14.8 - the two gauges are usually in complete agreement. Moreover, the Link 10's reading for the House battery when the engines are charging it, is consistent with the Yamaha gauges' readings when the engines are charging the start batteries.

From what I have been told, 14.6 or 14.8 volts is too high for charging an AGM battery.

I am absolutely NOT an expert on this stuff - just reporting what I've seen, read, been told.
 
One of the problems is that outboard motors are poorly regulated. (Some better than others), but with Suzuki, Yahama and Honda I have often seen voltages of 14.7 volts. My Suzuki 140 runs 14.4 to 14.7. I don't have enough time on the Honda 90 (16 amp alt on the carbonated model) and using the Link lite to know what the voltage characteristics will be, but the 130 I had on the C Dory 25 (measured by Link 10) was in the 14. 4 to 14.7 range. No harm to my AGM batteries on any of these motors.

Generally you want to avoid gassing of any batteries--and it is a variation of current and voltage to get the best charge characteristics. AGM will take up to 30% of their capacity per hour with no problems. On my RV and some other units with large battery banks, I have a temperature sensor on the battery charger (130 amps 4 stage on the RV). The temperature sensor is important to prevent gassing.

Here is a quote from one battery expert:
"The charging of AGM batteries can be done by applying a constant-voltage, where the charging voltage is held to a range of 2.3 to 2.6V (at 25°C) and the current is allowed to vary. This lends itself to higher rates of recharge without damage or reduction of lifetime. Complete charge times of less than 1 hour are possible (C/1 rate). " AT 2.4 volts per cell, this is 14.4 volts (which is generally accepted as the ideal charging voltage in absorption phase for AGM)--but at 2.6 this is 15.6 volts! Optima states that their batteries can be charged at up to 15 volts, both with alternator, charger and cyclic use. Keeping the charging voltage at 14.4 volts is very acceptable--if your outboard motor is that well regulated. However, for the relitatively short periods we run our motors going up to 14.7 volts most likely will not shorten the life of the battery.
 
Thanks, Bob, for all the good information.

My tentative conclusions about the premature demise of my AGMS:

1. The smaller Yamaha engines' alternators may not be as well regulated as the larger ones. I have two F50's. I do frequently see 14.8 volts on my gauges.

2. I probably run the engines for longer periods than average. Last year's 2000 mile trek, for example, included many long days of running with nothing other than the engine alternators charging the batteries. A previous similar trip with flooded cell batteries caused no problems. It may be that a little bit of 14.8 in shorter bursts won't hurt.

Whatever the case, I'm back to using flooded cell batteries.

(Note to Admin - we seem to have strayed from the thread title a bit. Maybe some of this on batteries could be moved?)
 
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