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[Kev]

Hello all just about finished my 6 month build from a set of plans obtained on ebay, she had her first voyage on the lake today here,s a few shots from the trip.

[baloo]

very impressive,now all you need is a lifeboat house & slipway to launch her.Well done young man

[Kev]

Hello

After checking out the boat after the first sailing I have 1 or 2 problems with the running gear and 1 with the paint.

1 The twin 540 motors were so hot after 20 mins you could not even touch them without burning yourself. Is this normal or are my 40mm props to big?
2 I am using a esc rated at 320amps max with both motors running from it, it also was so hot you could not touch it and all the labels on it fell of, it never stopped working and still did when the boat was taken out of water, this was a cheap ebay buy from hong kong.

3 The paint. The hull is abs and I put all the ribs in the boat to strengthen the hull with epoxy resin, the hull was primed and painted with plasticote spray paint, the white portion of the hull has gone a yellow colour everywhere where there is an internal rib fixed to the hull and where epoxy was used to fasten ballast this has also gone yellow on the outside. The white between the ribs and elsewhere is still brilliant white, this has got me really puzzeled anyone have any thoughts as to what went wrong with the paint?

[baloo]

Hi,i have two std 540 motors-2 x 35mm 4 bladed props-2 x 43hx electrolise esc run on 9.6 batt pak no problem,no over heating and on this battery pak i have working lights,folding mast,radar.So it is possible the props are to big and the esc (well forien import !!)I would sujest useing 2 x micro-magic esc (£25) 2 x  540 std motors and a 8.4 or 9.6 battery pak.The micro-magic esc can take up to 28v hope this helps in some way.baloo(martin)

P.S I think your lucky it did not catch fire

[Kev]

Thanks for your reply martin, I am only using a 7.2v stick pack with the 1 esc so I think my first mod will be to get 2 decent esc's and run them of a y lead with seperate batteries for each motor, I was a bit worried about the esc from hong kong after it got warm while testing in the bath so i never installed my detailed interior before going on the lake to make access easier if there was a problem..

Any thoughts on the paint problem?

[baloo]

Hi, on the paint problem that would be out of my hands.I only use halfords spray-can paints,i put undercoat on then what ever colour,but if you go to a crash repair shop that re-paints the crash vehicle`s they should be able to help out,if not put out a message about paint on mbm and see what reply`s you get.Martin

[irishcarguy]

Hi Kev I would suggest you take a look at ACTion's P94 for an ESC, it is two ESC's in one & also a mixer, Give Dave a call he will steer ( pardon the pun) right & answer any questions you may have. Mick B.

[gregk9]

The only time I have had problems with epoxy glue causing paint to discolour is when I ventured in to my local "poundland" and tried their stuff. Ok,its cheap, but it does not like water and degrades rapidly to the point of crumbling to bits, but it also give an early sign of failing by going yellow in colour, this also then reacts with its paint coating and "tints" this too.

If it turns out to be a simple lack of sufficient primer base, to prevent any colour from bleeding through, try a spray can of "sanding sealer", or "barrier coat", give it a couple of coats, and sand smooth, but make sure you dont sand "through" this barrier layer, or where you did, will bleed through again later on.  this stuff is also good for overcoating any paint you are unsure of its content, for example, overpainting enamel or oil based paint with cellulose , it prevents the thinners from reactivating the underlying paint.

[arunaddiction]

Hi Kev,

looks like a nice build and with a turn of speed (makes me want to start my 1/12 tyne but will have to wait for my arun to get finished first)

interesting problem with your paint going yellow, i worked in a body shop for years and we used to spray sealer or primer first on to stop stains bleading through from the sub straight, did you use 5 minute epoxy for the ribs? this has a habit of going yellow over time compared to slower epoxy's, and an additive or the hardener may have leached through the plastic, plasticote paint etches in to plastic so that it doesnt peel off so not requiring a primer and may have reacted. a call to plasticote may have an answer.

as to your motor esc problems, a single esc is imho the easiest way, i run several large cruisers 40" plus with twin 850 motor and only pull just over 30 amps on 50mm props! and run fine on a 40 amp single m troniks esc, 540s arent best suited to scale boat as they pull a lot of amps especially if over propped and run for long periods,  i have found 35mm is the biggest they can handle without melting, better to use a pair of 550-650 5 pole size motors with your 40 mm props and a single 40-50 amp esc running a 7.2 battery pack. ( twin esc's and mixers are overkill for a boat this size) i believe in keeping it simple and cheap and have alway had the best result working this way

hope this was helpful

regards Greg

[irishcarguy]

Hi Greg nice to see you back I was thinking of dropping you a PM, I wondered where you had gone, how is the lifeboat coming, it must be near done & I hope your hand has improved too. Sorry Kev for the temporary hijack but had not seen Greg post for awhile.( he has a very nice lifeboat build going ) Thanks to you all, Martin (baloo) any parcel yet, Mick B.

[Kev]

Thanks guys for all your help, I had been away from boat modelling for around 15 years and ventured into cars and can honestly say the help and advise I have received from this 1 post is more than i ever got on any car forum..

The epoxy I used was, yes pound land special  .  It does not appear to be showing any signs of discolouring or failing. The bottom of the hull has been sanded down and awaiting a few coats of sanding sealer, then a few coats of brilliant white again.

I have just ordered 2 johnson 600 motors to replace the 540's which were from old cars i had so the may of been past there best.

Thanks again for all your advise, think I am going to enjoy being back in to boats again..

kev

[Kev]

Here's a few more shots out of the water..



















These next 2 shots show the discolouration of the white, its a bit hard to see on the photos but can be made out just.






The life rings will change to the more common red and white eventually.. They were obtained from a free NHS stop smoking kit which came with a puzzel to keep your hands busy, once this was pulled apart and four of the pieces clicked together, the were the ideal size...

[Stavros]

One word in you paint problem springs to mind instantly to me is PLASTICOAT biggest load of poo pooh in my opinion regardless of what others say and I will quote well I use it and it works for me etc.
I made an error of judgement and dsprayed a sea queen years ago with this stuff and it went yellow within a coupe of sailings.


Dave

[Neil]

That geezer on the bow looks like Eddie Jordan, the BBC commentator and ex F1 team owner...........is he moonlighting as an RNLB crewman between races 

[Kev]

Just checked him out and he is the spitting image.. He must of posed for one of the figures in the world peacekeepers range.