Topic: Al Khubar build (Read 22370 times)

Del Boy · « **Reply #50 on:** January 20, 2018, 12:20:58 pm »

Hi, made some more simple progress. I installed the Deck Beam's (they do seem incredibly flimsy) and did my best to reinforce with quite a large amount of P38 and Epoxy. I guess they will hold now. Photo shows them masked up>

P1000690 by DEREK RULE, on Flickr

Then I gave the whole interior a quick coat of Halfords Grey Primer. I did this because on my last couple of boats (decades ago) I could not stop water ingress and the various wooden parts got swollen and were lots of trouble.

P1000692 by DEREK RULE, on Flickr

Not much planned now, lucky me off for a holiday! When I get back have to tackle the rudders, not looking forward to that as once epoxy's set they cant be removed!

Thanks for looking in,

Derek

longshanks · « **Reply #51 on:** January 21, 2018, 09:33:38 am »

Looking Good!
Wont be long and you'll have the deck on .....

Kev

Del Boy · « **Reply #52 on:** April 10, 2020, 07:14:26 pm »

So picking this up again after two years! Tackled the two Rudders. I trimmed the shaft to a slightly shorter length, roughed it up with a file and likewise inside the two Rudder halves. I then drilled a hole in the centre, used a two part rapid epoxy and using a small bolt and clamps set aside to dry. Hopefully will hold!

P1020824 by DEREK RULE, on Flickr

Del Boy · « **Reply #53 on:** April 12, 2020, 07:46:19 pm »

Added Lead ballast to Bow, Port and Stern. Surprised just how much was needed.

P1020832 by DEREK RULE, on Flickr

P1020834 by DEREK RULE, on Flickr

This is going to weigh a Ton!

Del Boy · « **Reply #54 on:** April 12, 2020, 07:54:14 pm »

Next up final checks to the Rudder linkage. Whilst I thought there was considerable space ended up with this very basic solution.

P1020831 by DEREK RULE, on Flickr

Have to be honest it did require some 'adjustment' to the deck support beam, not for operational reasons but just dismantling etc. if needed later on.

P1020826 by DEREK RULE, on Flickr

Final test revealed all Electronics working as planned plus Rudder's so that's a wrap then!

Del Boy · « **Reply #55 on:** April 12, 2020, 08:09:30 pm »

So my final efforts today. All wiring tidied up (receiver, switches etc. to fit later) and so this is my final format prior to fixing the Decks.

P1020828 by DEREK RULE, on Flickr

Forward Coamings in place

P1020836 by DEREK RULE, on Flickr

This feels like progress!

Derek
P1020828 by DEREK RULE, on Flickr

warspite · « **Reply #56 on:** April 13, 2020, 09:18:08 am »

The Ballast strip, should it not be lower in the hull, you appear to have fitted it above or very near the waterline, is this after a buoyancy test and any up top structure, has that been accounted for?

just wondered, I like your tidy up statement, wish I was that un-tidy

Del Boy · « **Reply #57 on:** April 13, 2020, 01:01:44 pm »

Really good points Warspite. As a complete newbie to this I took advice and it was suggested to get the weight as high up as possible in order to try and limit the inevitable 'bobbing' in a rough sea/pond. What I did was a 'bath test'. I added all the Styrene for the rest of the build in roughly the areas where it will end up. I then added all the white metal fittings again in a similar arrangement and then armed with Spirit Level set about balancing it all out with the Lead strips. Obviously I hope it works and don't doubt for one second the advice from a very experienced Sailor.

I do really appreciate you taking the time to comment, what are you building yourself?

Derek

Taranis · « **Reply #58 on:** April 13, 2020, 01:39:07 pm »

For stability all the weight should be along the keel and always as low as possible. Maybe I'm wrong I've not been modelling a great deal longer than you Derek but I've not come across anyone advocating placing ballast has you have been advised.

Looking good

derekwarner · « **Reply #59 on:** April 13, 2020, 02:35:06 pm »

mmmmmmm

.....best spend some time on Metrecentric point of Balance......

The simplest way to consider this is the speed of the arc of travel of the pendulum in the Grandfather Clock.......the longer the pendulum arm to the weight increases the time between reversal of direction. This in a model boat slows the speed of vessel roll, but increases the angle of roll

So lowering the metrecentric point reduces conditions such as ''bobbing'' and actually adds to realism in the vessel motion and roll

Having said this, bath testing is the logical path to determine the optimal location for ballast placement

Courtesy of the WIKI people

https://www.marineinsight.com/naval-architecture/intact-stability-of-surface-ships/

Derek [from Australia]

tugsov · « **Reply #60 on:** April 13, 2020, 07:13:17 pm »

Probably going a bit off topic here, but I'm not sure I buy into that explanation. The metacentric point is considered a fixed point in ship stability until a ship heels. It's the centre of gravity that you want to move. And the center of gravity will always move towards the weight that's added.

So if you add weight in the bottom of the Hull the centre of gravity moves away from the metacentre and the distance of metacentre to centre of gravity is increased, giving your vessel more stability, but the effect of this is faster rolls. If you add weight higher up the centre of gravity moves higher, and may end up above the metacentre, in which case you end up with negative stability and a capsize.

That's my understanding anyway, but the metacentric point doesn't move to my knowledge.

ballastanksian · « **Reply #61 on:** April 13, 2020, 08:15:25 pm »

I have heard and seen that putting ballast at the sides of a hull either on the bottom or just where the hull turns to form the sides gives a good balance between speed of wobble and height in the hull. I did this in my Destroyer and Monitor hulls and it seems to work.

warspite · « **Reply #62 on:** April 13, 2020, 09:20:54 pm »

I am certainly no expert - others are better at an explanation, to me though I high weight causes instability a low weight increases stability, that's to say the reduction of the possibility of a roll, weights fore and aft give better riding of the hull through waves so I have heard, never really built anything that could test the theory, only experience is my flower class corvette riding up and down violently at the bow and stern when all the weight was in the area under the rear part of the focsule on the hull bottom, see sawing effect, it could handle it like the real ship, just very disconcerting as a modeler.

Del Boy · « **Reply #63 on:** April 15, 2020, 06:57:36 am »

Many thanks to you all for your comments, input and suggestions, I really do appreciate them all.

I think maybe adding weight higher up was because I have a big Lead Acid Battery down low in the hull so hopefully pretty stable in that regard. I did do an on water test and to my untrained eye seemed OK but time will tell. I have the Decks down now so when final trimming is needed will definitely be loading up along the keel line. Thank you all once again.

P1020829 by DEREK RULE, on Flickr

Working on the Bulwarks now so will be a while

Derek

DaveM · « **Reply #64 on:** April 15, 2020, 09:43:38 am »

I notice that you've fitted the battery lying on its side and exactly along the centreline of the keel. Do be aware that in this orientation the battery is heavier on the side away from the terminals - because the lead plates are in the bottom half of the case when it's standing up normally - and that this might cause a list to starboard.
DaveM

Del Boy · « **Reply #65 on:** April 16, 2020, 11:22:23 am »

Ha! I wondered why I had to add weight to Port

did not know that so thank you very much Dave! When it comes to the final trimming I may well be able to adjust that to my advantage.

It seems like every aspect of this Hobby has a unique piece of interest, I have learnt so much from everyone already and not really got going yet, wonderful and thanks for your interest and support

Busy chopping out Bulwarks right now, what a job. Has dawned on me I will have to paint around this lot later

Thanks for dropping in.

Derek

Del Boy · « **Reply #66 on:** April 16, 2020, 11:57:56 am »

So, just wondering what Filler is best to use on Styrene? I have a rather eclectic mix to hand (of various ages I must admit !) so what do members suggest for easy sanding etc.?

P1020893 by DEREK RULE, on Flickr
P1020892 by DEREK RULE, on Flickr

Fred Ellis · « **Reply #67 on:** April 16, 2020, 01:30:10 pm »

My self I use the P38. then a bit of stopper if needed.

coch y bonddu · « **Reply #68 on:** April 16, 2020, 05:27:01 pm »

P38 is old hat and it simply leaver air holes far better off using easy light or one of the lightweight fillers that are 2 part ie filler and hardener,one of the best fine fillers on the market these days is a product called Dolphin glaze,can be used on any undercoat to hide a scratch for expample and does not leave and filler ringing marks on the surface.....Best place for the P38 is in the nearest bin sorry it does not have any place in our hobby far far superior products out there nowadays that rub down far far easier than that stuff.

Some of you will question this fact but believe you ME after 40 years on the car body trade i should know a thing or 2 about fillers,ask anyone in the trade what would they like an easy life or a difficult one i think i know the ans

Dave

DaveM · « **Reply #69 on:** April 16, 2020, 07:33:23 pm »

P38 does have its uses. I use it to make patterns for masters from which I then take silicon-rubber moulds and thence resin castings. It sets hard and sands very nicely, but in my usual applications it's only used once. For styrene filling I've always used Squadron Models' putty.
Nice to see my drawings of A-K still have their uses. They were originally drawn in pen onto tracing film so I don't have any digital copies. Those bulwark supports were as annoying to draw as they were to make, mask and paint!
Still, that's why we make model boats, innit?
Dave M

Taranis · « **Reply #70 on:** April 16, 2020, 07:52:26 pm »

I have found the new breed of squadron putty to be as much use as a chocolate fire guard
So many complaints that Leeds model shop readily accept returns

Del Boy · « **Reply #71 on:** April 17, 2020, 11:36:04 am »

Thank you all for your comments, much appreciated. So I have P38 but ……………….. absolutely rock hard from ages ago so that's been dumped! So decided to take Dave's advice and ordered the Dolphin Glaze from Lord Amazon, will let you know how I get on.

Interesting Dave M that you were involved in the original drawings, I have found them all very clear so far. I did duck fitting the Prop Nozzles through, try as I might I just could not get them to fit and have a clean driveline so they are in the Bitz box

Now back to those Bulwarks!

Thanks for connecting in this crazy time!

Derek

neverupright · « **Reply #72 on:** April 21, 2020, 08:41:22 pm »

Hi Derek

thanks for the kind words about my superstructure on my thread, got to say your progress is looking awesome, motors and everything look bang straight, a lot neater then mine are looking, keep up the good work, longing forward to following your progress.

Carl

Del Boy · « **Reply #73 on:** April 26, 2020, 07:14:39 pm »

So kind of lost my way a bit this week. I was discussing the 50 or so Bulwarks, fitting and then the tedious job of having to mask all round when I came to spray the Decks and sides with Longshanks. He suggested I paint them now and fit the Bulwarks afterwards. I thought this was a great idea so took a good hard look at the state of Decks etc. and had to get the Filler out in what seemed like a never ending task. I had bought some Dolphin Glaze as suggested by coch y bond du and was very pleased, it is as smooth and silk and easy to sand too thank goodness. So have spent the week fitting the carriers for Bow and Stern Fenders and aforesaid filling and sanding. Hoping to finish that tomorrow and do some trial spraying.

P1020908 by DEREK RULE, on Flickr

P1020914 by DEREK RULE, on Flickr

That's all for now, stay safe and keep modeling!

Derek

Del Boy · « **Reply #74 on:** May 05, 2020, 11:17:53 am »

So I have spent the weekend fixing the Gunwales to the top of the Hull perimeter. Got there in the end and would suggest that anyone doing a similar job spends as much time as they can to bend the tube/wire into a near perfect shape before committing to the Cyno. I also had a challenge fixing and or securing whilst the Cyno set, in the end simply put some wood strips across the top and gently weighted it all down. Clean up next, bit of filling and final painting of the Hull and Decks can start.

P1020928 by DEREK RULE, on Flickr

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Author Topic: Al Khubar build (Read 22370 times)