Boat weight question

[Stein]

Well, I just got some surprising news from the local Cat scale.  My 18' RH Seahawk came in at 3055 pounds on the trailer which is about 900 pounds heavier than I guesstimated and over the trailer rating.  The trailer is rated 2200# but I put 3220 pound rated tires (combined) and 3000 pound springs on it, I don't know what the axle is rated as it has no markings.

The manufacturer has the boat at 1230 dry, here is what I calculated:

Boat dry 1230
Mercury 90CT - 363
Yamaha 9.9  93
34 gallon main tank - full 204
Spare fuel (2.5 gallon) 15
Extra seats (2) (it came with 2 and I added the two back benches, I assume the front 2 are in the dry weight)  60
Two batteries 80 (assume they aren't in the dry weight)

Gear 100 (I took the downriggers, weights, rods, etc out so it just has life jackets, tools, flares, misc junk)

That puts the boat weight at 2145 which isn't close to 3055 - 910 pounds heavy.  I'm probably forgetting a thing or two but 900 is a bunch.

The scale also had the tongue weight at 700 exactly which is hugely heavy and 19.9% of the overall boat + trailer weight which isn't good either.  This is actually the reason I weighed it because it seemed a bit heavy and I was wondering if I should move the boat back a bit on the trailer.

Unfortunately, it's the only scale around my area so I can't get a second opinion but I would be surprised if it was off that much.  I was thinking of picking up a tongue weight scale and at least double checking that but I thought I would ask around here first to see if that weight sounds realistic and if anyone sees something I'm missing.

Unless I'm missing something I need to buy a 3500-3700 pound trailer as I'll load a couple hundred pounds of gear on the boat for combo shrimp/crab/fishing trips.

Weights from the scale with boat:

Steer 3240
Drive 2720
Trailer 2820
Gross 8780

Without boat

Steer 3120
Drive 2140
Trailer 0
Gross 5260

[Stein]

Well, I found one mistake.  For the re-weigh, I had to go in, pay for the first one and then he did the re-weigh when I was at the register, so I was in the truck for the boat weigh and not in the truck for the re-weigh.

That roughly puts tongue weight at 425 which is 13.1% and realistic and the on trailer weight of 2780 which is still 635 pounds heavy.  That still seems like a bunch of extra weight I can't account for.

[fishngamereaper]

You got foam under the deck... I've seen boat's add hundreds of lbs with water absorption in the floatation foam from the factory.

[huntnphool]

 Pull the floor boards and make the drain holes in the bracing bigger. I’m betting you have a floor full of water.

[RockChuck]

Maybe I missed it but did you add in the weight of the trailer in your calculations?

[Stein]

Maybe I missed it but did you add in the weight of the trailer in your calculations?

I did, subtracting that out the boat is 2780 and my calcs were 2145, so I'm still 635 heavy.

I could pull the middle section of floor which would only require removing 2 seats and then the floor, but even if I'm 50% wrong I'm 315 pounds heavy which is 38 gallons stuck somewhere.  It's only 3 years old and stored inside with the plug out, so I'm thinking it's highly unlikely that 38 gallons was absorbed in the floor.  There is space between the foam and hull and water can flow freely bow to stern in the bottom.

The easy button is to buy a 3700 pound trailer for $4,840 plus $254 for the swing tongue plus tax.   

[RockChuck]

I see it now 🤦🏻‍♂️😂

[fishngamereaper]

You would be surprised how much water that foam will hold...I pulled some year's ago and each hand full weighed a lb or two.  Probably took 300 lbs out of a 16.5 boat.

[Skillet]

Does the boat manufacturer's dry weight include the Mercury?  That 90 hp weighs 363#.

I know back when I was looking at boats like Hewescraft and Alumawels and such, they didn't include main in the dry weight, since you could rig it with any number of engine options.

[Dukalr]

I agree, 1230 lbs is WAY too much for that motor..... I’m pretty sure that’s where the miscalculation is.  I bet you’re fine weight wise for that trailer

[Stein]

Yeah, typo from my spreadsheet.  I had the numbers right there, just transposed them wrong here.

Boat is 1230 dry
90CT is 363 dry

Fat fingers, bad eyes and old age creeping up on me.

I sent an e-mail to the manufacturer to verify 1230 is the right number for my model year and to see if they have any insight.

I also read from a trailer guy that claims 90% of boats are overloading trailers, manufacturers skimp on the trailer because like me, not many people crawl under there to check the weight rating and then scale the boat before purchase.

I noticed there is a big gap between the common 3500 pound axles and the 6,000.  There are a few in the 4200 range, but not many and hard to source springs.

Anyone know a good trailer shop in the Everett to Mt Vernon area?  My current setup is bolted on the frame, so I could simply remove that and have someone weld me up a brand new suspension and axle.  I tried the one in Everett, but they actually wouldn't even talk to me when I drove in there last year.  Worst service I can remember. 

The other option is to run with what you brung.  I have several thousand miles on this one and it hasn't launched the boat out on the highway yet.

[huntnphool]

Maybe I missed it but did you add in the weight of the trailer in your calculations?

I did, subtracting that out the boat is 2780 and my calcs were 2145, so I'm still 635 heavy.

I could pull the middle section of floor which would only require removing 2 seats and then the floor, but even if I'm 50% wrong I'm 315 pounds heavy which is 38 gallons stuck somewhere.  It's only 3 years old and stored inside with the plug out, so I'm thinking it's highly unlikely that 38 gallons was absorbed in the floor.  There is space between the foam and hull and water can flow freely bow to stern in the bottom.

The easy button is to buy a 3700 pound trailer for $4,840 plus $254 for the swing tongue plus tax.   

 You may be surprised to find that much water in there, but this is coming from someone with a boat as well.

[Mfowl]

Check out Six Roblee's in S Everett. I replaced/upsized my trailer axle and springs through the Tukwila store several years ago when a spindle was damaged. They were great and knowledgeable to work with plus the price was very reasonable. I bought all the parts there and did the work at home in an afternoon. I did have to launch my boat and get it off the trailer to complete the work.

[Buzz2401]

I've known multiple people whose aluminum boat leaked like a sieve from that factory.  Two were North rivers.  Don't know anyone with a RH Seahawk but would not surprise me even a little if you had a small leak letting in water. 

[huntnphool]

I've known multiple people whose aluminum boat leaked like a sieve from that factory.  Two were North rivers.  Don't know anyone with a RH Seahawk but would not surprise me even a little if you had a small leak letting in water.

 NR boats are made with a one piece bottom and I’ve not seen a single issue among several friends that own them. What most people fail to think about is the amount of water used to wash the inside. If the drain holes get clogged, all that water sits in the hull, unseen, under the floor panels.

[CP]

Here an informative video on where RH puts the foam in their boats and some issues with water drainage.  Not the same model but I'd bet they use the same techniques in all their models.

 

[Fishstiq]

My boat, new and totally empty, was 5580lbs with trailer. Add fuel and all the gear for fishing (downriggers, tackle, safety gear, coolers with ice that I never need cause I don't catch anything, lunches, snacks, water.....) And I was up to 6380lbs, an 800lb gain. 504 of that was fuel. So, roughly 300lbs of gear.

600+ pounds you can't account for, man that's a lot of weight. Water is what, a little over 8lbs/gallon?  I'd have to echo what others have said and look into water under the floor and possibly in any foam. Let us know when you get it sorted, I'd love to hear where it's all coming from.

Also +1 for Six Roblees, never used them for boat stuff but I've done plenty with them for truck stuff and they've always been square with me.

[Ridgeratt]

Id guess you could contact Ez-Loader in Spokane and get a torsion axle set up for it. Their web site has all the parts. appears most of it is bolt up.   

If you use your "friend" Google it shows the link.

[Stein]

Here an informative video on where RH puts the foam in their boats and some issues with water drainage.  Not the same model but I'd bet they use the same techniques in all their models.

Thanks CP, it gives me a target to look at.  The bow of mine is completely different, no foam on the hull but the back is probably similar with the exception of the huge gas tank down the middle.  I would say most of the foam is above deck, they foam out the gunnels on both sides and then two huge chunks above the deck under the back.  There is barely room for the battery back there and a tiny opening to the bilge.

I know the boat doesn't leak, zero water is ever in the bilge unless I'm washing the deck down or bringing water in by crabbing or swimming.

It will be interesting to see what the manufacturer says about their dry weight number.  They give a single number for that model but there are multiple configurations.  I have big stainless fish box up front and a couple of other options so that is probably some of the weight.

Boats that size are very weight sensitive and I know I haven't lost any mpg or top end speed as the engine syncs to the Mercury app which gives me all the data.  I'm still getting 6.5 mpg at cruising speed loaded, just like when it was new so I don't think there is an extra 300-600 pounds under the deck or I would certainly see it in performance and economy.

Regarding the other post about Six Roblees, I had a spring issue last year, drove it down there and they guy was even reluctant to come out and look.  He looked for about two seconds and walked back in the store and said "I can't help you."  OK, I get it, they don't sell the spring I need.  I followed him in and said what if we pull all that stuff off down to the bare frame, what would it cost for you guys to weld on new hangers and put new springs and a new axle on there.  He said "no, can't be done."  The current suspension is all bolted on to the frame, so I could have a clean frame in 20 minutes and they obviously had zero interest in even selling the stuff or doing the work, so I'm not sure what their problem was.

I'll pull some deck out today and see for sure one way or another.  My current guess is the factory dry weight number isn't accurate for my model year with my options.

[Stein]

Well, me wishing for dry foam was not effective.  The good news is the design is pretty cool, there is a channel running on both sides to divert water from the deck to the bilge.  You can see it on the left.




Sent from my iPhone using Tapatalk

[Stein]

The bad news is there is nothing in the front to keep water out of the foam channel.  Every time I hosed the boat out, it ran straight into the foam channel.  The piece you see that stops in the middle there is the front of the channel that runs the length of the boat I mentioned last post.

Not the best design.




Good news is the boat is aluminum so I just need to rip it out, fix the front to prevent the problem and pour new foam in.

I also pulled 100.1 pounds of gear out and there is plenty still in the boat so those numbers were off.  The extra seats were heavier and I forgot about the fabric top as well.  Looks to be a combination of extra options, more gear and water.

I’ll weigh the foam I pull out.


Sent from my iPhone using Tapatalk

[chiwawadan]

Interesting thread to a boat noob such as myself. Appreciate threads like this.

Best of luck cleaning that all up, Stein.

[fishngamereaper]

I'm sure your plywood floor weighs twice as much as it's supposed to..

That foam to aluminum contact creates hidden corrosion so look for pitting. I wouldn't put similar foam back in..some sort of closed cell product works best..even the pink foundation insulation works better.

[Stein]

I'm sure your plywood floor weighs twice as much as it's supposed to..

That foam to aluminum contact creates hidden corrosion so look for pitting. I wouldn't put similar foam back in..some sort of closed cell product works best..even the pink foundation insulation works better.

Yeah, I did some quick googling and found people using the sheet foam from Home Depot, pool noodles and even ping pong balls.  My thoughts now are that it's going to be hard to keep those two foam channels completely dry with a three piece floor.  There are the two joints running across the floor as well as the floor to channel seal.  Over engineering would be to seal the foam channel, pour foam and then fiberglass over the top and then the floor on top of that but I don't think fiberglass will bond to aluminum well, not to mention problems with flexing.

I wish I could replicate crab floats, those things absorb nothing even when in the water for a long, long time.  I think they might have some type of cover over the foam to protect them or I could just cut up a bunch and jam them in there.

A final crazy thought is a bunch of yoga blocks, but they are pretty expensive in quantity.

Anyway, cheaper than a new trailer and will keep me out of trouble the next few days that are supposed to be windy and rainy.

[CP]

Now I want to pull the floor boards from my RH and peak underneath.  I've been wanting to change the foam in my Arima for years but there is no easy way to get in there.

[Stein]

Total foam weight was only 65.8 pounds, maybe 10% saturated, 60% wet and 30% dry.

The hull design is such that water sits in there when it’s on the trailer.  Here is how far I had to lift it to drain it all out the back.




Sent from my iPhone using Tapatalk

[Stein]

Sent from my iPhone using Tapatalk

[Stein]

Some weight will come out, but mostly this fixed the problem before it was real bad.  The floor boards are pretty heavy, I will probably replace with new ones varnished don’t they don’t absorb water.


Sent from my iPhone using Tapatalk

[Stein]

I’ll finally get to address this mess as well, I didn’t have room when I put it in to do it right.  It wasn’t that bad, I had to disconnect everything to get the floor out.




Sent from my iPhone using Tapatalk

[huntnphool]

 Glad you got it figured out, nothing like "while you're in there" projects!

[Stein]

Got it washed out, at least good enough for under the floorboards.




Sent from my iPhone using Tapatalk

[blackpowderhunter]

looks great.
feel free to shoot me a message if you have any questions regarding the new decking.  i did a similar project on my old north river, was a 2006 with saturated floors and foam.
I did a 2 part epoxy to seal the marine grade plywood and then wrapped in nautolex vinyl, then used a staple gun with stainless staples hooked up to my compressor to glue and staple the vinyl down.
i think this is the epoxy i used to seal the wood
https://www.jamestowndistributors.com/userportal/show_product.do?pid=97636

[Stein]

looks great.
feel free to shoot me a message if you have any questions regarding the new decking.  i did a similar project on my old north river, was a 2006 with saturated floors and foam.
I did a 2 part epoxy to seal the marine grade plywood and then wrapped in nautolex vinyl, then used a staple gun with stainless staples hooked up to my compressor to glue and staple the vinyl down.
i think this is the epoxy i used to seal the wood
https://www.jamestowndistributors.com/userportal/show_product.do?pid=97636

Thanks, I was thinking about many coats of varnish but it looks like that might penetrate and hold up better.

Did you coat both sides, I'm assuming yes.

Is the one quart kit enough?

What vinyl and adhesive did you use.  They sure don't give that stuff away.

[blackpowderhunter]

looks great.
feel free to shoot me a message if you have any questions regarding the new decking.  i did a similar project on my old north river, was a 2006 with saturated floors and foam.
I did a 2 part epoxy to seal the marine grade plywood and then wrapped in nautolex vinyl, then used a staple gun with stainless staples hooked up to my compressor to glue and staple the vinyl down.
i think this is the epoxy i used to seal the wood
https://www.jamestowndistributors.com/userportal/show_product.do?pid=97636

Thanks, I was thinking about many coats of varnish but it looks like that might penetrate and hold up better.

Did you coat both sides, I'm assuming yes.

Is the one quart kit enough?

What vinyl and adhesive did you use.  They sure don't give that stuff away.

yep, coated both sides.
i also pre drilled all of the holes for 'screws' that hold the decking down and filled them in with the epoxy to penetrate there, hoping to eliminate points of entry.
im 99% sure i only used the 1 qt kit but at this point i cant remember...i searched through my emails for the receipt but cant find it.
i used to nautolex glue, not cheap, but i figured if i got bubbling or non stuck areas after all that work id be pissed if id used 'inferior' glue, so i bit the bullet.
https://www.defender.com/product.jsp?id=23788#

when applying the vinyl i glued it down, used a flooring roller to really smooth out any air bubbles, flipped over and stapled one side and then pulled it reallllly tight and stapled the other side.
having an air stapler really helps here because you're putting them in every few inches, and a regular staple gun will give you some hand cramps quick 

[Stein]

Thanks, I have an electric stapler with stainless staples from previous projects, so I'm loaded there.

I'm off to the hardware store for round 1 of purchases.  I'm also expecting a grey van later today with more goodies.

Did you do one or two coats on the epoxy?  Looks like 1 should be good for new wood, but they don't say for sure.

[blackpowderhunter]

i did 2 coats, the second coat was more of a finishing/touch up/fill in areas that soaked up more than others though.

[kball4]

I recently did a complete tear down of a Lund Fisherman 1800 I am rebuilding and I was astounded by the amount of water in the foam.  I re-poured with 4lb closed cell foam which is denser than the recommended 2lb foam most boats come with.  I also fiberglassed in the floor boards and put a bead of marine 3M caulk along the edge to prevent any water from getting through the floor again.

[Stein]

Well, I hoped to post pictures of all the foam done today but somehow I ordered the 6 lb instead of the 2 lb and noticed the difference after pouring a 2 quart kit.  If anyone wants to make their own crab buoys, the 6 lb foam would do it.  A 2 quart kit (1 quart each A and B) only makes .75 cubic feet vs 2 cubic feet for the 2 lb foam.

I'm thinking the 6 lb foam would be highly impervious to water, it's literally hard as plastic, even a bit harder than a crab buoy which obviously can be in the water a really long time before it gets water logged.  The bad part is the price, it's the same cost but you would have to buy 2.5 times more foam and it's $52 for a 2 quart kit.  A guy wouldn't want to have to pull that out of the boat, it would pretty much be a permanent thing.

We have family coming in for the 4th, so I'll likely put the boat back together sans foam, run it over the weekend and then find a 3 day stretch I won't be using it and tear it back apart and pour the new foam.

I did decide against replacing the floor.  It dried out probably 80% and for some reason there is a shortage of the flooring adhesive such that nobody has it in stock.  That, coupled with the $400 price tag for the wood, flooring and adhesive and we'll get at least 2 more years out of this floor before I get the itch to replace it.  The flooring itself is in really good shape and there is no rot in the wood, it's 100% solid everywhere.  I did put two coats of epoxy on the underside so it won't be getting any more water, but won't be drying out from that side either.

On the good side, I was able to reroute the fuel vent so I don't have it blocking access to the bilge and the wiring is all tidied up.  I reglued both the bilge pumps and created 3/4" drains through the side parts of the boat and 1.5" from the bow to the bilge.  I have three hopefully watertight foam compartments and the boat shouldn't hold water up front.  I'll post pictures when I get a chance.

I have some ideas that might help others as this issue is likely present on 99% of the boats under 20' that have plywood floors not sealed to the hull which is basically all of them.  Boat builders could do it "right", but virtually nobody would pay for something they can't see when the other builder is selling his for less.  My guess is it would add $500-1,000 or so to have watertight foam compartments, epoxied wood and proper drains, maybe even more.

Anyway, one way or another she will be on the crab in a few days even if we have to sit on milk crates.

Good times.