Have been offered a wooden boat, kit built, but the owner says it is heavy.

Is there any way of making a heavy boat lighter? I presume that water has soaked into the hull, but don't know if wooden hulls are solid or shells like the GRP ones.

Desperate ignorance here, can anyone shine a light? 

I take it that’s it’s a racing boat which is above class weight. In which case you maybe able to reduce weight by new electrical parts particularly batteries and winches. Has the boat any corrector weights that can be removed? It could be damp but this suggests it’s not well built. You might be able to drill holes in some of the bulk heads if you can access the inside but don’t endanger strength. 

Hi David, without knowing more details I think it’s difficult to answer your question.

I believe many older IOMs were built from wood using various techniques and some, by modern standards, may have been a bit “overbuilt”. So the age of the boat may have some bearing on it’s weight. To my mind it’s not likely that water is the problem, because it’s easy to dry a boat out. So a heavy boat would probably need a lot of modification and reconstruction to shed any significant weight. Not impossible to do, but might not be worth the effort!

Wooden boats don’t have to be heavy. There are some excellent posts on this forum summarising recent builds, such as the well known ‘Alternative’ design. I believe it’s possible to build an underweight boat from cedar planking, so that correctors are required to bring the boat up to minimum weight.

I bought a second hand Lintel from the classified section of this forum, complete with 3 rigs, rig box, transmitter, stand and measurement certificate (it has correctors glued inside the hull). It’s an older boat, but professionally built from glass and perfectly fine for reliable club racing. In fact it’s quite quick in stronger winds. I’m only a beginner at radio sailing, but from my brief experience I would honestly recommend waiting to find something similar. That way you can focus on the important “dark art” of boat set-up, rather than spending a lot of precious time on re building a boat that might never be competitive. That’s just my view; I’d be interested to hear other’s opinions too.

Good luck and best regards

Martin 

 

 

 

Hi David

I am new to RC sailing but have built many full size boats and own a cedar strip built IOM which carries correctors,it seems common practice for wooden RC boats to be coated with either epoxy or polyester resin and reinforcing cloth which can easily add a lot of weight if not carefully done.To avoid overloading any boat with un nessesary resin either vacum bagging or peel ply need to be used which ensure excess resin is removed after wetting out the reinforcment.

If the builder has not done this the boat can be lightened by sanding back possibly to bare wood and recoating with lightest cloth and peel ply is the easiest as the material is wrapped over the wetted laminate and peeled after curing to remove excess then sanded using a long board to get a fair surface and finishing with thinned paint/varnish,not too much as these add weight too.

Its worth asking the seller how the boat was built and what wood was used I could be just a matter of sanding and refinishing .

Good Luck

Graham

 

Hi Graham and thank you. I would be interested to hear about your full sized boats - cedar strip?

I have discovered that the boat I was looking at is 25% overweight, so have decided against. I was hoping to be able to dry it out and re-waterproof, but that much water could cause all sorts of problems. Maybe the answer is to build one myself, using the methods you suggest.

Thank you for yoiur interesting advice.

David

Thanks also to Martin and Martyn,

the boat is too far away for me to be able to make a full investigatiopn of all the possibilities you have raised, but you make some very interesting points which I will be able to use if I come across another wooden boat nearer to hand.

Wood is a wonderful medium, and modern methods can make wooden boats much less work intensive, but it looks as if tbere are parallels between full size and models. I was one of 7 crew on an American schooner years ago - constant maintenance for all of us. My previous boat had been GRP and half the size - just me doing constant maintenance!

Agree with Martin. (And he is doing much better than he lets on)

I would love to have the time to restore a boat, but with limited time a second hand boat from here to discover the dark art of tuning, let alone master the art is what I am trying to spend my time doing, and sailing it, but I am a sailor and not a model builder and there are clearly different  approach to this sport.
A secondhand IOM from here, and just sail it and then faster and faster for me works well….(club members on sat, will now refer to this post when I fail to win next weekend)

Personally I would recommend that, even a beginner, should not consider an overweight boat as it will be extremely frustrating to sail and make you think you are a worse sailor than you actually are.

Excess weight hurts you in two ways: Firstly it increase the wetted area (higher displacement) which increases viscus drag and secondly it slows acceleration (F = Ma).  The latter is particularly galling as you will loose out tacking and rounding marks.  If you sail inland then, when a puff comes everyone else will sail away from you as you will be slower to accelerate.  

There is a reason that most classes have a minimum weight limit and arguably those that don't ought to, to prevent the current trend in ultra-fragile boats that are severely damaged by even a modest collision.

Yes, I was thinking about acceleration, but wetted surface area is even more important in light airs. 

Good advice. Thank you. I WILL be patient. 

I WILL be patient. 

I WILL be.... 

😬

Hi Everyone,

I have followed this thread with interest and although I tend to agree with some of the thoughts and science on the water, I don’t think it is all doom and gloom. I commissioned sometime ago for a Sushi (IOM) to be built. Unfortunately, the end result was the boat ended up over weight by approximately 50 grams with A-Rig fitted. The comparison of how much additional weight is in the IOM is simply a battery pack within the radio pot. 
 

Obviously, it is not ideal and any skipper would rather not have an extra battery pack weighing their IOM down. However, on the positive side, considering wetted surface area, the hull doesn’t sink to much more into the water, less than half a millimetre actually. Plus extra weight will allow the boat to keep the momentum going when other IOMs may have stopped in light wind conditions. We are not talking world beating, highly expensive IOMs here. Over weight IOMs are still competitive in the club and district level. They would also provide a challenge for talented skippers sailing overweight boats against other club members. 
 

Why do I say this. 

Please read my scores from the Joint Services regatta. On the first day (Up to race 11), the wind was barely on the lake and the fleet was drifting for much of the day. Admittedly my scores suffered. However, on the second day the wind gradually increased to a medium to strong A-Rig breeze. Apart from some bad sailing on my part, from race 12 - 27 my scores improved dramatically. Hence it is not all bad to have an over weight IOM as the attached scores prove.

JT

16 hours ago, John Taylor said:

Hi Everyone,

I have followed this thread with interest and although I tend to agree with some of the thoughts and science on the water, I don’t think it is all doom and gloom. I commissioned sometime ago for a Sushi (IOM) to be built. Unfortunately, the end result was the boat ended up over weight by approximately 50 grams with A-Rig fitted. The comparison of how much additional weight is in the IOM is simply a battery pack within the radio pot. 
 

Obviously, it is not ideal and any skipper would rather not have an extra battery pack weighing their IOM down. However, on the positive side, considering wetted surface area, the hull doesn’t sink to much more into the water, less than half a millimetre actually. Plus extra weight will allow the boat to keep the momentum going when other IOMs may have stopped in light wind conditions. We are not talking world beating, highly expensive IOMs here. Over weight IOMs are still competitive in the club and district level. They would also provide a challenge for talented skippers sailing overweight boats against other club members. 
 

Why do I say this. 

Please read my scores from the Joint Services regatta. On the first day (Up to race 11), the wind was barely on the lake and the fleet was drifting for much of the day. Admittedly my scores suffered. However, on the second day the wind gradually increased to a medium to strong A-Rig breeze. Apart from some bad sailing on my part, from race 12 - 27 my scores improved dramatically. Hence it is not all bad to have an over weight IOM as the attached scores prove.

JT

And of course the greatest affect on position is the skill and experience of the person steering!

Edited December 18, 20223 yr by ianrmcdonald
Pushed the wrong button!

Hi

I have built a number of wooden IOMs over the past 2 years and not one of them has been overweight. By using well engineered construction you do not have to put a lot of timber into the hull. A well built woody is very strong, so much of the internal structure needed on a plastic boat is not required. My latest boat was built using Obechi ( usually use Western Red Cedar) for the planking and came out about 240 grams light ( includes A rig and battery). below is an image of the boat and evidence of the weight using my own scale that was checked using the calibrated scales at Gosport. 

Tom, Both boats look amazing with your use of contrasting strips of wood and the stunning finish you’ve achieved. I might have a go at cedar one day, but I’m not confident of creating something as pretty as those! Thank you for sharing your photos - Would you mind telling us what design(s) they are and the basic construction approach (e.g. did you use glass inside/outside)?

On a separate note, I’m relieved the IOM rules are such that home building can still produce boats that are competitive. The various parties who have contributed to the rules as they stand deserve a pat on the back. Yes, a professionally built boat is a quick route into getting on the water with a competitive boat, but as documented in various posts on this forum, there’s still room for enthusiasts to design/build/restore boats to sail at pretty much any level.

1 hour ago, Tom Roberts said:

Hi

I have built a number of wooden IOMs over the past 2 years and not one of them has been overweight. By using well engineered construction you do not have to put a lot of timber into the hull. A well built woody is very strong, so much of the internal structure needed on a plastic boat is not required. My latest boat was built using Obechi ( usually use Western Red Cedar) for the planking and came out about 240 grams light ( includes A rig and battery). below is an image of the boat and evidence of the weight using my own scale that was checked using the calibrated scales at Gosport. 

Lovely boats Tom

The lighter boat is an "ADRIATIC" by Ceccarelli and is basically a wooden SEDECI, so far the design is looking very competitive.. The darker coloured boat is my own design, it is called RHUMBA. It has a very low wetted area and a waterline length of 950mm, it performs well in lighter conditions but has enough buoyancy up front to take gusty conditions in its stride. The aft deck was made using a mold but a wooden deck is similar weight  I am going to build my next boat in sitka spruce, it is slightly heavier than cedar but is very strong and durable.

I usually line the inside  hull and underside of the deck in glass tissue and WEST epoxy. On the outside i use 2 coats of WEST, flat back and a third coat which is then flatted back up to 2000 grade then polished using trade vehicle cutting polish. Apologies for drifting off topic, perhaps i should open a new thread on building wooden boats. I have added a couple of building images but i have loads if people are interested.

52 minutes ago, Tom Roberts said:

The lighter boat is an "ADRIATIC" by Ceccarelli and is basically a wooden SEDECI, so far the design is looking very competitive.. The darker coloured boat is my own design, it is called RHUMBA. It has a very low wetted area and a waterline length of 950mm, it performs well in lighter conditions but has enough buoyancy up front to take gusty conditions in its stride. The aft deck was made using a mold but a wooden deck is similar weight  I am going to build my next boat in sitka spruce, it is slightly heavier than cedar but is very strong and durable.

I usually line the inside  hull and underside of the deck in glass tissue and WEST epoxy. On the outside i use 2 coats of WEST, flat back and a third coat which is then flatted back up to 2000 grade then polished using trade vehicle cutting polish. Apologies for drifting off topic, perhaps i should open a new thread on building wooden boats. I have added a couple of building images but i have loads if people are interested.

A thing of beauty Tom! I am not sure I could enjoy racing one as I panicked on each cross, up the beat. Or does the epoxy coat deal with collisions ok?

My money would be on the wooden boat !  Because of the construction they are very strong, main problem would be a high speed t-bone but i have never had a problem. I look at it as a race boat so treat it like any other boat. It is probably easier to maintain a boat like this because at the end of the day its just a lot of lolly sticks glued together, in the event of a crash just get more lolly sticks !

23 hours ago, Tom Roberts said:

The lighter boat is an "ADRIATIC" by Ceccarelli and is basically a wooden SEDECI, so far the design is looking very competitive.. The darker coloured boat is my own design, it is called RHUMBA. It has a very low wetted area and a waterline length of 950mm, it performs well in lighter conditions but has enough buoyancy up front to take gusty conditions in its stride. The aft deck was made using a mold but a wooden deck is similar weight  I am going to build my next boat in sitka spruce, it is slightly heavier than cedar but is very strong and durable.

I usually line the inside  hull and underside of the deck in glass tissue and WEST epoxy. On the outside i use 2 coats of WEST, flat back and a third coat which is then flatted back up to 2000 grade then polished using trade vehicle cutting polish. Apologies for drifting off topic, perhaps i should open a new thread on building wooden boats. I have added a couple of building images but i have loads if people are interested.

Tom I would think a Wooden boat build thread would be enjoyed by all classes. I look forward to seeing it.

On 13/12/2022 at 11:44, Stephen B said:

Agree with Martin. (And he is doing much better than he lets on)

I would love to have the time to restore a boat, but with limited time a second hand boat from here to discover the dark art of tuning, let alone master the art is what I am trying to spend my time doing, and sailing it, but I am a sailor and not a model builder and there are clearly different  approach to this sport.
A secondhand IOM from here, and just sail it and then faster and faster for me works well….(club members on sat, will now refer to this post when I fail to win next weekend)

ahem, you failed to win last weekend  

1 hour ago, Andrew Start said:

ahem, you failed to win last weekend  

But it was a DF weekend

Tom

Looking at the photos of your beautiful wooden hulls I noticed you are using arm winches. Are the arms homemade or for instance K-Bits (No longer available). What servo are you using to operate the arm? Also if programmed what settings are you adjusting? How many degrees of movement do you require?

The Hitec Monster Power winch servo at the moment seems difficult to source. Wondered if you were using the Futaba S9177SV or an import steering servo for a monster truck? I aquired a 35Kg standard size servo which using the transmitter I can achieve approx 120 degrees of rotation.

Sorry for the Hijack of thread. 

Thanks Eric 

I am currently building a Corbie 6 from cedar and ply decking. Despite what I thought was minimal internals I have estimated that It will be 100gms overweight.  I  have removed the cedar strip foredeck reduced the foredeck bulkheads to skeletons sanded the internal hull which was light epoxy coated back to a minimum but only achieved 50gms back. Now going to re-make foredeck in ply which I hope will achieve enough saving. 
I appreciate that on occasions a bit of extra weight can be helpful, but when racing knowing you are overweight is always going to play on your mind and the reason you blame the boat not the man on the sticks. I am surprised that West Epoxy is used on some builds as it is much heavier when used as a coating. I also I think their can be a marked difference in the weight of cedar and any other planking as you buy small amounts and  have a limited number of suppliers who are not on your doorstep.

Martyn

I’m unsure if you have read my comment further up this post. Your IOM being overweight is not all bad. Of course, we always aim to be at the minimum weight, but it’s not the end of the world. Keep persevering you will get there.

JT

A glass composite boat can be made lighter for the same strength, stiffness and toughness as a wooden boat.  A carbon composite boat will be even lighter.  My understanding is that the IOM minimum weight has been set so that home built wooden boats can achieve the minimum weight.  Thus a wooden IOM is practicable but for other classes with more aggressive (or no) minimum weight, a wooden boat is not really viable.  Wood may look pretty but it's engineering properties are poor compared to modern composites and they are also quite variable so you can get unlucky and get a heavy or even weak batch.

Not sure about other classes but i am glad the IOM class rules leave the door open for the home builder. If what you are saying is correct ( and i have doubts about the stiffness ) it means that sailors are in the hands of a very limited number of people with access to complex molding facilities and an autoclave. Surely this means that for these classes it is  expensive and is a limiting factor on development and class numbers. The option to turn a design idea into a working model is just not there. Sorry, but i just like wood.