Todays Boating

[ashley needhamParticipant @ashleyneedham69188]

Hi Fred. A fascinating read, if SLIGHTLY dated! So much stuff he left out…fibreglass, Styrofoam, vac-forming, 3-d printing…brushless motors, Li-Po batteries, 2.4 gig radio, rattle cans, superglue. How we have come on!

A good reference actually if you are making something “vintage” or even repairing something.

It’s up for grabs, free if anyone wants it. Not you Fred, at 40p, you have the updated version!

Ashley

[ashley needhamParticipant @ashleyneedham69188]

Skid boat proving difficult. Seemed to go ok with a modified wedge taped in place, but still the back was lifting and there was some cavitation. Tried the “pt boat” underwater shape and the thing just dived nose first in the wTer. Not sure how this could be as there was considerably more foam under the front of the bow than with the wedge? It’s baffling. Then, on a third try out with the wedge, it didn’t go aswell as the first time?? Battery still at 8v.

If weather good on Tuesday might try another session with a couple more u derwater bow shapes, and a 2200Kv motor.

Rob’s cat displayed “errant. Behaviour and ran mock, leaping over the log and ramming g the pennyworth…ignoring g radio control mand and still going  with transmitter off. Poled it off the weed and eventually after a couple of slow large circles control was regain3d ???  I did notice the stubby trial on the Planet receiver was missing g…..

Ashley

[ashley needhamParticipant @ashleyneedham69188]

Wowser wowser. Skidboat success at last!

Moving the prop forward has by and large stopped the cavitation, however adding a lead weight of 288gm to the rear sorted it out completely. With two tunnel wedges in place the boat was fast on its 2200 Kv motor ( on 2s). Less happy with a flat backed wedge due to skipping.

it might be interesting to have another go with the plan u derwster shape just to vindicate the original design. If the original shapes do not work, the tunnel form  ( big wedge forward, lower wedge after this, but with the centres cut out in a longitudinal manner) will still give the same ‘original’ look from the side.

If the plan had shown the expected waterline, we might have had more success earlier on. Building too light…who would have thought it would give us trouble!

Weight off my mind! Ashley

However, the prop would not work where it was as it was pulling air down even with the stern held well under.

[Dave ReedParticipant @davereed72029]

Building too light…who would have thought it would give us trouble!

I once had a crack at building an airboat entirely from foamboard. Covered it with sticky back plastic (Blue Peter style) to keep most of the water out. Light as a feather and plenty of power with 2S, 2200Kv and 7×4 prop.

Trouble was, the slightest gust of wind or ripple on the water and it would suddenly and unpredictably change direction. Sometimes “add lightness” isn’t the answer.

By the way, paper covered foamboard is not a suitable building material for something that’s going to get wet!

Dave

[Colin BishopModerator @colinbishop34627]

Ashley,

Presumably there must have been something about the original design which made the model work back in ye olden daze otherwise it would not have been published. It would be interesting to try to identify the discrepancy from that original design to your modified successful model. Back in the day, getting sufficient power might have been an issue (weak batteries, inefficient motors), could that give a clue?

Colin

[Dave Reed]

On Dave Reed Said:

Building too light…who would have thought it would give us trouble!

I once had a crack at building an airboat entirely from foamboard. Covered it with sticky back plastic (Blue Peter style) to keep most of the water out. Light as a feather and plenty of power with 2S, 2200Kv and 7×4 prop.

Trouble was, the slightest gust of wind or ripple on the water and it would suddenly and unpredictably change direction. Sometimes “add lightness” isn’t the answer.

By the way, paper covered foamboard is not a suitable building material for something that’s going to get wet!

Dave

I think any material has its merits as long as it is suitably treated.  I used to have a steam powered model that had a hull made from resin impregnated paper laid over wood frames.

[Dave ReedParticipant @davereed72029]

Hi Richard,

The foam airboat was basically an experiment in building as light and quick (less than a day) as possible – too light in this case. Protecting the material wasn’t a major concern at the time.

However, I do agree that proper treatment could have waterproofed it. Your comment reminded me of a technique I saw in a book using a wood former to make a hull with gummed parcel tape. Liberal coats of shellac are used to seal it.

I’d rather not be the person to lick all that tape though.

Dave

 

[Colin BishopModerator @colinbishop34627]

No need to lick it, just pass it across a saucer of water. Very useful for simulating plating strakes too as on my Miltiades model.

Colin

 

[ashley needhamParticipant @ashleyneedham69188]

Colin is a fan of gummed paper strip!

The skidboat is supposed to have glow or diesel, and would have has an unsophisticated prop. We were wondering if the new prop was not liking being stuck out in the open and hence the sucki g down of air. Obviously the original, at 14 inches and solid balsa would be heavy for the size compared to ours.

I am going to try the original.plan underwater shape once more now the prop had been moved.

Depron and a hot glue gun is the way to build a very lightweight airboat, but it would be very fragile.

Ashley

[Dave ReedParticipant @davereed72029]

Depron and a hot glue gun is the way to build a very lightweight airboat, but it would be very fragile.

Depron… That’d be the grey foam stuff with no paper covering :-

Current project…

I was planning to use some fibreglass cloth/Eze-Kote on the bottom of the hull and a little ply reinforcement this time though. Adds some weight and strength.

Dave

[ashley needhamParticipant @ashleyneedham69188]

Dave. Yes depron is that stuff.

Is that 10mm styrofoam? Likely won’t need much to strengthen. As its light there is no momentum to collect dings and dents, but glass tissue and ezekote helps, however an epoxy resin is really required for a hard surface.

All our airboats have a small water rudder (extension of the main air rudder) and a sharks fin about 1/3 the way back from the bow. The sharks fin makes a massive difference in stopping drift, while even a small water rudder makes the boats much more usable when there’s any sort of breeze about…something that will affect yours as it will be very light.

Richard tried an airboat once here using foamboard and it was megga light…however it was probably twice as heavy as a depron craft!

The next project is reverting to a brushed 500 motor for several reasons. It’s supposed to be fast, and I have a selection of marked and unmarked cans, however there is a really wide choice to be had in the buggy fraternity (rock crawlers and so.on in 1/10 scale. They are quantified by the amount of ‘turns’ presumably the windings. And some hot ones do 30,000 rpm on a ‘buggy’ pack…7.2V.

Ashley

[Dave ReedParticipant @davereed72029]

Is that 10mm styrofoam? 

It’s 6mm depron with a ply reinforcement for rudder mounting.

Going to use motor/prop etc from the foamboard one that fell apart after a few weeks of dunkings and modifications. I’ll start without the fin then add one later to see the difference.

Dave

[ashley needhamParticipant @ashleyneedham69188]

Tested the skidboat last Sunday with the final tunnel hull underwater shape and it went OK. Week before that I did try the original underwater shape and it cabitatedcstraight away.

Oddly a small RTR was brought down by someone and this had the prop well astern of the transom and went OK. But it was a cat hull.

In hindsight it might have been interesting to have tried the tunnel hull with original prop position but hey ho. At least the tunnel hull gives sort of the correct plan side view. Boat currently on top of the fridge in the warm so that the epoxy resin and fibreglass on the tunnel wedges will dry sooner rather than later. Trevor has to cut his boat about now to mirror mine.

Such is life

Ashley

[ashley needhamParticipant @ashleyneedham69188]

Ok. Update. Painted epoxy resin on the Skidboat foam wedges and they hardened up nicely. Glass matt was applied to the underside of the front wedges only, as these will be the ones bashing into logs and so on, and on the bench the boat will rest on them so they needed armouring.

Throughout all of this the finish of the hull has escaped unmarked ( thin glass cloth and epoxy over builders foam) and currently I am painting the underside. More work needs to be carried out internally…mount for fake engine, fake fuel tank and the clacker.

Ashley

[ashley needhamParticipant @ashleyneedham69188]

Last Sunday the 1st was a washout. I went down to test the hss ( now I have adjusted up the propshafts and relieved any thrust on the motors. Which is what I think the vibration was)( and it was fiddly as although there is access into tje pontoons, it’s slim, and the props are partially shrouded by the outlets) but it started to rain almost as soon as I opened the box, and alsobthe Christmas ferry top stayed uncovered.

Better luck thus Sunday.

Silver paint(?) Pens are really very silvery, if I have not mentioned it before. Ditto uv setting metallic nail Polish. A lady in our dancing group had her nails done in gold and it really looked like a gold overlay. Might investigate…

Ashley

[ashley needhamParticipant @ashleyneedham69188]

It’s incredibly gusty here. With rain in the air and mone too warm so I think this Sunday will be a miss.

Not many opportunities to get the ferry Christmas top an outing remaining before Christmas. Seem to recall it was the same last year..

Ashley

[Len Morris 2Participant @lenmorris2]

Hi Ashley,

Nail polish works very well as I found out recently.  I’d weathered mi winch pulleys to look grimy but wanted to brighten the middles where the ropes would have rubbed.  Tried silver paint but they just didn’t look right.  Then my daughter visited and she had polished steel finger nails!  Not silver or chrome, they looked like stick on shim steel.  Out of a bottle and not uv setting.

Definitely worth a look.

Len. 🙂

[ashley needhamParticipant @ashleyneedham69188]

Len. Will look at nail Polish next time I want to glam something up.
<p style=”text-align: left;”>I have loads of soldiers I painted as a lad with Humbrol silver, and those bits are just that. Very shiny silver. Modern Humbrol just dull in comparison.</p>
we are going for Tuesday morning at the pond for boating, weather allowing.

Ashley

[Len Morris 2]

On Len Morris 2 Said:

Hi Ashley,

Nail polish works very well as I found out recently.  I’d weathered mi winch pulleys to look grimy but wanted to brighten the middles where the ropes would have rubbed.  Tried silver paint but they just didn’t look right.  Then my daughter visited and she had polished steel finger nails!  Not silver or chrome, they looked like stick on shim steel.  Out of a bottle and not uv setting.

Definitely worth a look.

Len. 🙂

A particularly useful metal finish is Humbrol Metalkote paint.  You paint it on and then, when dry, buff up the surface with fingers, soft cloth, brush etc.  This leaves a very impressive shiny surface.  There is also a huge range of metallic paints from Alclad, which I haven’t used but the plastic modellers get some very impressive metallic finishes with it.

[Colin BishopModerator @colinbishop34627]

the plastic modellers get some very impressive metallic finishes with it.

The problem with many, if not most of these metallic finishes is that they are not durable. OK for plastic models which are intended to be displayed and not touched but the finish is easily damaged on a working model. You can protected it with lacquer but this inevitably dulls the brilliance.

Some of the pens are good, Molotow Liquid Chrome for example. Nail polish certainly seems worth a look but it only lasts a week if that on fingernails. Might be longer on models but you would need to do a few experiments.

You can get metallic acrylics which will take lacquer. The finish is not very shiny but it does look like bare metal such as steel, gunmetal or aluminium.

Trimline Tape from Model Technics comes in quite effective silver and gold which is useful for decorative trim and window frames. I used the silver on my Fairey powerboat windscreens.

Colin

 

[Len Morris 2Participant @lenmorris2]

All excellent recommendations.  Trouble for me is that in darkest Lancashire the only source is the internet which invariably ends up costing a tenner.  Nail polish is available all over and very cheap.  A long time ago I fell asleep towards the end of a family party and woke to find the kids had painted my finger nails all different colours.  Took forever to wear off!

Len. 🙂

[ashley needhamParticipant @ashleyneedham69188]

There’s no easy way round it.

Boating Tuesday dismal. Besides being quite cold, the wind got up when we got there, then there was rain in the air…to compound this,Trevors Jessie rower was jumping gear, the lander ferry was just dead…no life at all and HMS Midge torpedo boat had no motor control…dead…AND it’s servo was slow and very noisy. Possibly the noise was due to lack of use and the slowness was due to the esc, however we didn’t feel like tinkering in the cold (besides having no spares) to rectify these issues so scarpered back to base for tea and mince pies.

A travesty all round.

We instead spent some hours looking at home made vacuum forming kit. As we saw it, the vacuum box via a Henry hoover is easy, but heating the plastic evenly over an A4 sheet could be tricky. Then there is the cost of the plastic, which is no especially cheap, and you know you will use at least 10 sheets just getting it set up properly.

However. Infra red radiant fires are cheap and possibly the three row sort might be big enough, area wise for the job. Food fo thought next year.

Ashley

[ashley needhamParticipant @ashleyneedham69188]

Today’s boating good. Full crew, mild, relatively windless.

Ferry now ok after rudder servo change.

HMS Midge also now ok after reseating and squeezing up the bullet connectors for the motor! Easy fix. Servo still noisy…might see how it goes.

Full bore Christmas boating next week…santa hats, mince pies and festive music (the Christmas ferry deck has a large ‘present’ on it that is space for a noisy thing sound unit) BESIDES having christmassified boats.

Ashley

[ashley needhamParticipant @ashleyneedham69188]

Bit nippy at thr pond today! Wi d got up and it was jolly brisk. Car park only half full.

Last outing for Xmas ferry deck for another year.

Ashley

• 

[Colin BishopModerator @colinbishop34627]

Very festive Ashley.

Colin

[Author]

Posts