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[red181]

I would take 3rd choice, by far most labour intensive, get it back to wood, start fresh, it may not be reacting now, but imagine if in  a months time it all starts going funny, after all this hard work , if its back to wood, you can then also sanding seal it, if painted with household gloss the hull may have pourous imperfections that might open up at a later date, if ambitious enough you could glass fiber it! , like I said earlier, I am not a paint expert, but have learnt the hard way, ignoring the warning signs now could be costly at a later date, 

[triumphjon]

i can imagine most of us have been faced with the same problem , at least if youve started from a bare model you have a fair idea of what its painted in ! if removing all of the existing paint isnt a viable option then at least barcoat will stop the reaction , and seal it from the fresh paintwork . i now make a note of what my models are painted in , should i sell them this is passed onto the new owner . jon

[stevesteve]

not saying it cant react later but my thoughts were that after any solvents had evaporated off and paint had fully hardened then a reaction shouldn't be possible? i can see how it could produce a weaker finish though.

I'm still trying to figure out what path I'm going to take, personally i cant see myself stripping it right down, i don't think the hull is up to it with the ribs and all. i think I'm only left with 2 options where i would keep my sanity.

cover with sealer or try and work around the issues with my dry coat technique.

i will make some inquires with sprayers to see what it would cost for the sealer coat. i suppose it could even be brushed on then sanded flat if all else failed.

[Welsh Wizard]

Steve PLEASE listen to what I am saying here,a dry coat textechnique will NOT work.As for the paint fully hardened yes it has BUT The solvent in the new paint will eat into the old ain't and soften it thus giving you a reaction.As for brushing the barcoat it is a big NO NO................WHY i hear you ask,Well Barcoat is used to seal any form of old paint and stop further reaction,if you rub it down you will without a doubt go thru it in places,Barcoat is like water to apply it is microscopically thin that is why.If any sprayer charges you more than a tenner to put it on they are robbing you blind in my opinion,if you want to send it up to me then I will do it for FREE I allready have barcoat in the unit pm me if you want it down I will also throw some primer over it so it will be ready for you.


Dave

[Norseman]

Hi Steve

If you do strip it down (and it honestly looks like the way to go) I am told that 'Fairy Power Spray' at about £3.15 in
Tesco's will do most of the hard work. I am about to try it myself on old paint for the first time - but the chap who
advised me has been 100% right in all the advice given me so far....... no pressure intended Steve, it's your choice
mate. Good luck whatever you decide to do 

Dave

[stevesteve]

welsh wizard, can the coat be put straight over the the work Ive already done? the whole hull was sprayed and 99.9% is fine on the hull with no reactions, just the 3 small spots i mentioned before and would hate to strip all that off, the work, agghhhhh! the other side to going over it is that the wife wont see me stripping off a load of paint Ive just paid out for, instead just adding to it he he.
When i said about solvents having evaporated off and paint hardend there shouldn't be a reaction, i was not talking about the old original paint being solvent free and not reacting as new was put on.
what i meant was any new paint that has successfully gone on without reaction and has fully dried and hardened shouldn't react later on.

Norseman,

Ive heard people talking about power spray too.

[triumphjon]

barcoat is applied directly over the object with the existing problem , it dosnt need sanding afterwards but merely overpainted in whatever paint you wish to continue with . it will save you hours of removing every scrap of whatever the model has already been coated in ! jon

[stevesteve]

barcoat is applied directly over the object with the existing problem , it dosnt need sanding afterwards but merely overpainted in whatever paint you wish to continue with . it will save you hours of removing every scrap of whatever the model has already been coated in ! jon

so any painting that has already been done does not need to be removed, just bad areas flatted?

[red181]

thats a hell of an offer, getting it sealed and primered free!

I have used the fairey power spray myself, it works very well!, removed several coats of household paint and only required minor rubbing down and scraping, then a very good wash down and drying off for a long time to get rid of any residue 

[stevesteve]

so glad that you dont get this problem with paintwork on modern cars, just nightmares getting all traces of wax off the area.

[Norseman]

Hi Steve - I see you don't sleep much either
Dave

[stevesteve]

Hi Steve - I see you don't sleep much either
Dave

na i dont sleep much, its 5.25am now!
part of my condition make me unable to  sleep untill completely exhausted, i cannot shut off and have gone more than 48 hours without sleep quite a few times!

[Norseman]

Ah yes - Mayhemitis will do that to you 

Look at the medical thread - we all seem to be damaged goods mate. 

The models are in better shape than us all.

Dave

[Welsh Wizard]

Steve no need to strip existing paint off send it up and leave the rest to me.


Dave

[stevesteve]

BREAKING NEWS!

Steve has sanded the affected areas and blown over them again but now with no problems. all other areas are holding out without any sign of trouble

[stevesteve]

I bet when i finally get this finished the cold weather will have frozen over the lakes and ponds!
If it were a surface drive craft the snow would be good fun, check out what this bloke does with his racing model in the snow lol.

http://www.youtube.com/watch?v=vuNt0PUahTY

wonder if he thought about the extra load on the motors along with the water cooling not working!

[Norseman]

Hey Steve

I'm just having a last mooch around before I go to work  - how's she coming along?

Dave

[stevesteve]

things slowed because of Christmas but got some bits done since my last post-
 
hull is now in gloss white, above the deck still needs painting.
Made a new motor mount, aligned it and bonded it in.
fitted motor.
made bracket for the rudder servo and fitted it.

I have tested it in the water at last!
having real problems finding somewhere to take the boat without having to drive 20 odd miles, theres no bloody ponds or lakes! eventually i went to a ford in a river that runs slowly and the kids and i had a play with our boats there.
its not very fast although i was fighting the current as i did not want to risk going with it due to a 6 inch waterfall on the right side! I'm running 8.4v, so going up to 12v will give me some gain and I'm going to experiment with prop sizes once i get the cooling installed (have not installed a water pick up yet)
the boat had a short run and the motor only got mildly warm without any cooling so with cooling i think a larger prop is not going to be a issue although it may not actually make it faster, testing is  the only way to find out.
I will also look into putting a much more powerfull motor in it at a later date, the aim now it just to have it painted and running, it does not need to be fast to enjoy playing with it.
in 1 pic the universal joint looks like it does not reach its insert properly, it does the shaft was just pulled back at the time of the photo from working on it.
gonna start on the topside and interior as soon as i get some spare money.
heres some pics of it now.

[triumphjon]

its starting to come together now , nice to see its being used !

[MikeA]

what prop u got on it?

i seen now on a previous post your using a 35mm prop.

did anyone answer the question to what the L + R means? im interested myself

[stevesteve]

what prop u got on it?

i seen now on a previous post your using a 35mm prop.

did anyone answer the question to what the L + R means? I'm interested myself

its got a 35mm prop on it at the moment, the most recommended was a 38mm but where i got my bits from did not have a 38, just 35 and 40.

No, i never did get a response from anyone regarding running the motor in both directions, here is the spec of the motor copied from the graupner site-

Specification
Operating voltage range  4,8...12  V
Blockierstromaufnahme 65  A
Diameter 42,2  mm
Free shaft length 14  mm
Case length 67  mm
All-up weight, approx.  320  g
Maximum efficiency 75  %
No-load current drain (A)  2  A
Charging rate at max. efficiency 12,5  A
Permissible motor direction  R   
No-load speed 15000  U/min
Nominal voltage 9,6  V
Shaft diameter 5  mm

As you can see, it clearly state permissable motor direction, other models they make have L+R in the specs. i know that there are some wiper motors that are designed to be run in one direction only. these will run slower in reverse or not run at all.
this graupner motor i have runs slightly slower in reverse polarity, the problem is although I'm pretty sure that damage is not going to be caused by the short periods that reverse is used and really should be ok for continuous running i dont know for sure.   
I will do a bit of research as ive not looked into it really, just asked on here.

[triumphjon]

the L & R  is the rotation of the prop , most vessels that use more than one motor will  use contra rotating propshafts , this helps the vessel to run in a straight line .

[MikeA]

I must comment on something and im sure ill be shot down about it. I have no experience of using a 700 motor but im very suprised to here it got warm spinning a 35mm prop! I use a graupner speed 600 8.4v with a 34/25 2 blade prop and that runs cold, plus a 540 motor spinning a 35mm prop and that gets warm.

I would have expected a 5 pole 700 motor to be more than adequate to run a 35mm without getting into a sweat. I may be wrong but are you sure there is no binding, its all spinning free and the coupling is nice and straight, Personally i dont like HUCO couplings as they are noisy and would much rather go with a MMB rubber type. In fact you can make one yourself using the brass ends from the HUCO coupling and connect them with some rubber hose!!   

An educated guess would sugest that the 40mm would be ok to get some grip on the water and to fettle about with the pitch rather than the diameter to get the speed up to expectations.

anyway

Just re reading ive allready said 40mm before and people disagreed so we ended up at 38mm. I personally would try a 40 if it was my boat but thats me.

[triumphjon]

its time to experiment with different props , both in diameter and pitch and diffenet numbers of blades , all of which have an effect on the current draw of any motor

[stevesteve]

mike, when i say mildy warm, i mean with freezing hands the motor felt mildy warm.
with very cold hands, things that would feel cool or even cold normally will feel a little warm even the cold tap in your bathroom.
any motor put under load will produce heat to some degree by design but the motor was not getting hot or even near hot, just able to feel a slight warmth in it and does not have any form of cooling working at the moment.
I took great care to make sure everything was aligned properly before things were permanently fixed, there is no binding and everything turns nice and freely and runs with little or no vibrations other than that from normal motor operation
I will be buying a couple of props and a 40mm will be one of them, trial and error will produce the best performance.