Author Topic: Bow thruster install  (Read 3251 times)

0 Members and 2 Guests are viewing this topic.

Bruceter

  • Newbie
  • *
  • Posts: 32
Bow thruster install
« on: August 15, 2014, 16:07:36 »
Hey fella's, I need a little help with my bow thruster install. First question can I glue this in to the wood with the epoxy glue that i'm using now with the wood? Secondly should I finish the planking completely and then line up and cut a hole for the thruster tubes or should I install the thruster and tubes and plank down around it? I do realize that i will need some backing around the tubes for the planking to glue to and to flare the opening to the back side a bit.

Thanks Bruce
Sorry about the two pics not sure this is happening?

][URL=http://s1100.photobucket.com/user/bruceter4/media/Smit%20Rotterdam/DSCN0588_zps214eb5be.jpg.html][/url]


des

  • Sr. Member
  • ****
  • Posts: 398
Re: Bow thruster install
« Reply #1 on: August 15, 2014, 23:31:28 »
G'day Bruce

If you fully plank first, then cut the bow thruster hole, will you be disappointed if you over-cut and have to fill the hole?  This is quite a possible outcome, 'cos none of us are perfect, and lining up the holes from one side to the other can be problematic.

I think if I was using  individual plank-on-frame, I'd line up the bow thruster tube within the framework first, then plank up to the tubes.  Maybe more fiddly in the first place, but I think it will give the better result.

You will still have an issue cutting off the surplus tube length to the hull sides - but you should be able to cut the tubes a little long, then grind them down to the final level using your Dremel.

And yes, in most cases you should be able to use the same epoxy to glue the plastic tubes to the hull planking, unless the tubes are nylon, poly-carbonate, or some poly-ethylenes.  I'd try it on some scrap pieces first.  Sometimes it only needs for the plastic to be scratched up a bit to give the epoxy something to key to.

Des.

Jarvo

  • Jr. Member
  • **
  • Posts: 98
Re: Bow thruster install
« Reply #2 on: August 16, 2014, 08:16:37 »
HI Bruce

Im of the opposite opinion. fully plank the hull, this gives a strong structure, cut your holes and epoxy the tubes in place. if you plank up to and around the tubes it only takes a knock to split the hull. Fully planked and resined inside, should be as hard as nails.

The bow thruster looks like the tubes come off, if thats the case, while you have room around the pump / motor housing, form a support base for the motor, remember to keep the screws etc accessible when the hull and deck are complete, (guess how i learnt that????)

The tubes will need scuffing with 120 ish paper to give the epoxy a key.

When you do come to resin seal the inside of the hull, use something like easycote or epoxy resin thinned with Meths only needs a little to make it runny, pore it into each compartment in turn and roll the hull side to side to waterproof the insides

Keep the photos coming, we all like a look and you get some great ideas.

Redads

Mark
Etherow Model Boat Club

PHILNZ

  • Full Member
  • ***
  • Posts: 212
  • Nelson sunshine capital of NEW ZEALAND
Re: Bow thruster install
« Reply #3 on: August 16, 2014, 23:29:42 »
 ^-^    Finish the planking first then carefully measure and cut the holes. I say this as you will maintain the natural curve of the hull , also it will stay stronger if resin in place too. to plank up to the tubes will require probably to much filler to regain the shape . My thoughts anyway .


Phil

des

  • Sr. Member
  • ****
  • Posts: 398
Re: Bow thruster install
« Reply #4 on: August 17, 2014, 14:06:53 »
Hi Bruce,

I must say, Jarvo and Phil have put up convincing arguments for finishing the planking first.  I'm converted.

Des.

Bruceter

  • Newbie
  • *
  • Posts: 32
Re: Bow thruster install
« Reply #5 on: August 17, 2014, 17:41:57 »
Hi Bruce,

I must say, Jarvo and Phil have put up convincing arguments for finishing the planking first.  I'm converted.

Des.

Well Des, I had it glued in before I had a chance to read Jarvo and Phil's recommendations. LOL
I was leaning myself to install the the thruster and then work the planking around the tubes myself. I figured I had a better chance of getting the thruster tubes level to the rest of the hull than trying to get two holes in the right place.  ;)
As to Jarvo's suggestion about epoxying the inside of the hull, I did epoxy resin all of the framing and the ply wood sections on the bottom of the hull before I started planking. I'll give it a second coat when I treat the planking the same way.
I'm sure my next questions will be regarding setting up of the motors, shafts and the Korts nozzles. I'll give it some time on the suggestions before I jump into it.  :)

Thanks for your help fellas
Bruce

Jarvo

  • Jr. Member
  • **
  • Posts: 98
Re: Bow thruster install
« Reply #6 on: August 18, 2014, 02:11:31 »
HI Bruce

NO worries on any advice, we learn by mistakes!!!! possible you could remove the outlet pipes on the bow thruster and plank over then cut backot fit the out lets????

The reason for the epoxy in the hull is to stop expansion and contraction due to damp and drying out, splitting the hull planking. I have just spent 3 months stabilising and renovating a 30+ year old hull, the joints were fine, it was the planks that had split!!!!!! remember use meths to thin the resin, you use less and it soaks into all the nooks and crannys, as well as soaking into the planks themselves.

Your need to set the running gear, have you bought the bits and when are you going to start????

You can make a jig before hand to keep the shaft U/J solid a small piece of copper pipe cut length ways to fit around the U/J clamped with a small jubilee clip,
once the motor and shaft glue has sett remove the clamp and do the other side. As for the Kort nozzles make a jig to the same diameter as the inside of the nozzle, a hole in the jig centred and a hole for the prop shaft, bolt it tight and you centre the shaft and the nozzle. clamp and mount the nozzle to its mounting and epoxy into position.

Caution. have a few practice runs before committing to the glue stage, then lay out your components.

Hope this gives a guide, shout for more help

Mark

Etherow Model Boat Club

Calimero

  • Sr. Member
  • ****
  • Posts: 268
    • Calimero's RC shed
Re: Bow thruster install
« Reply #7 on: August 18, 2014, 03:51:55 »
Another way of thinning epoxy is to heat it. Or actually heat the surface you want to glue with a hairdryer. Careful: epoxy will set much faster when heated up.

Jarvo

  • Jr. Member
  • **
  • Posts: 98
Re: Bow thruster install
« Reply #8 on: August 18, 2014, 05:10:43 »
Calimero is right, but heating epoxy can cause weakness in the glue itself. 24hour epoxy is 5x the strength of 90second.

Using Meths to thin the epoxy does slow the setting time slightly, 5 min epoxy sets in about 15 mins, the warmer it is the faster the the meths evaporates, but it does not weaken the chemical bond of the adhesive itself.

Plus you need runny epoxy to get round the hull to seal any cracks etc.

Mark
Etherow Model Boat Club

Calimero

  • Sr. Member
  • ****
  • Posts: 268
    • Calimero's RC shed
Re: Bow thruster install
« Reply #9 on: August 18, 2014, 07:50:07 »
I'm not sure heating would induce weakness. z-poxy recommend heat curing (80-90C) for maximum strength. Araldite gives shear strength figures after curing at 40C.

But I agree that a slow curing resing is recommended to waterproof a hull. Over the couple hours the resin stays fluid, gravity can do it's job and get epoxy everywhere.

Bruceter

  • Newbie
  • *
  • Posts: 32
Re: Bow thruster install
« Reply #10 on: August 19, 2014, 19:35:46 »
HI Bruce

NO worries on any advice, we learn by mistakes!!!! possible you could remove the outlet pipes on the bow thruster and plank over then cut backot fit the out lets????

The reason for the epoxy in the hull is to stop expansion and contraction due to damp and drying out, splitting the hull planking. I have just spent 3 months stabilising and renovating a 30+ year old hull, the joints were fine, it was the planks that had split!!!!!! remember use meths to thin the resin, you use less and it soaks into all the nooks and crannys, as well as soaking into the planks themselves.

Your need to set the running gear, have you bought the bits and when are you going to start????

You can make a jig before hand to keep the shaft U/J solid a small piece of copper pipe cut length ways to fit around the U/J clamped with a small jubilee clip,
once the motor and shaft glue has sett remove the clamp and do the other side. As for the Kort nozzles make a jig to the same diameter as the inside of the nozzle, a hole in the jig centred and a hole for the prop shaft, bolt it tight and you centre the shaft and the nozzle. clamp and mount the nozzle to its mounting and epoxy into position.

Caution. have a few practice runs before committing to the glue stage, then lay out your components.

Hope this gives a guide, shout for more help

Mark

Hey Mark,
I have heard of thinning the epoxy resin with denatured alcohol, but it seems it's not available in Canada for some reason. When you mention meths? Are meaning like methyl hydrate?

I do have some of the bits as you call them for the running gear. I'm using from the Billings kit the fixed Kort nozzles and the shafts and shaft tubes. I ordered the correct props for the Korts Raboesch #149 50mm 4 blade props, universal joints and for motors I have MFA  540 motors with 6:1 gear box. I really appreciated the help from Calimero here on the site really helping me out with what kind of rpm I heeded for the props I have. The 6:1 gearing could be on the low side. I'm new to this RCing so I would rather it be a bit slow at first until i get some confidence running it. If I want more speed I can eventually  swap out the 6:1 motors and gears with the same motors with 2.5:1 gears.

Thanks Bruce

Jarvo

  • Jr. Member
  • **
  • Posts: 98
Re: Bow thruster install
« Reply #11 on: August 20, 2014, 00:01:13 »
HI Bruce

Please accept my apologies, i forgot you were in Canada. Denatured alcohol and Methylated Spirit are the same product.

Isn't Methyl Hydrate frozen methane?

Try in a Hardware store, i think its used for thinning  shellac and some paint. 

Might be banned because some down and outs drink it. Ours has a chemical added to stop them

Mark
Etherow Model Boat Club

Bruceter

  • Newbie
  • *
  • Posts: 32
Re: Bow thruster install
« Reply #12 on: August 20, 2014, 18:58:13 »
Hey Mark, no need to apologize. Thanks for the clarification. I'll check it out. Methyl hydrate is something we use here to keep moisture from freezing in fuel lines. I'm sure it has other uses as well.

Bruce