Model Boat Mayhem

Please login or register.

Login with username, password and session length.
Pages: [1]   Go Down

Author Topic: Rigidity and Buoyancy  (Read 1629 times)

LJ Crew

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 102
  • Model Boat Mayhem is Great!
  • Location: South Buckinghamshire UK
Rigidity and Buoyancy
« on: June 26, 2018, 10:20:57 am »

Has anyone used the expanding foam from Screwfix to fill empty spaces in a hull and provide rigidity and buoyancy? From the spec it looks as though it is "open cell" and will absorb water. The reviews on the "B&Q" version are not good but Screwfix's are better. Experience and advice please.
Logged

Plastic - RIP

  • Inactive
  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 1,255
  • Bobbing Along!
  • Location: Watford
Re: Rigidity and Buoyancy
« Reply #1 on: June 26, 2018, 11:50:03 am »

I use it sometimes - my boats contain no wood so there's nothing to damage if any water is absorbed and trapped between the foam & hull.
The main purpose is anti-sinking so if the boat is completely filled with water, I can still get it back.
I also use polystyrene beads mixed with waterproof PVA glue in confined spaces to fill voids and compartments.
Logged

Bob K

  • Bob K
  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 3,686
  • Location: Windsor
Re: Rigidity and Buoyancy
« Reply #2 on: June 26, 2018, 12:07:17 pm »

Personally, if you intend going down this route please use a closed cell PU foam.
An open cell foam is likely to soak up water like a sponge, which could defeat the object you are trying to achieve, and can't be bailed out using a syringe.
Logged
HMS Skirmisher (1905), HMS Amazon (1906), HMS K9 (1915), Type 212A (2002), HMS Polyphemus (1881), Descartes (1897), Iggle Piggle boat (CBBC), HMS Royal Marine (1943), HMS Marshall Soult, HMS Agincourt (1912)

tsenecal

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 495
  • Location: Arvada, Colorado, USA
Re: Rigidity and Buoyancy
« Reply #3 on: June 26, 2018, 05:26:21 pm »

some of the over the counter expanding foam that comes in a spray can, available at hardware stores, also will never actually stop expanding...  never fill a void completely, otherwise a few years down the road, you may find a a bulge or a crack where the foam has expanded beyond the volume of the void.
Logged

unbuiltnautilus

  • Portsmouth Model Boat Display Team
  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 3,154
  • Location: Portsmouth, England, third rock from the Sun....
Re: Rigidity and Buoyancy
« Reply #4 on: June 26, 2018, 06:18:53 pm »

Roll up some bubble wrap...
Logged
Listen politely, nod approvingly, then do what you want, works for me!

Netleyned

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 9,051
  • Location: Meridian Line, Mouth of the Humber
    • cleethorpes mba
Re: Rigidity and Buoyancy
« Reply #5 on: June 26, 2018, 06:51:59 pm »

Roll up some bubble wrap...


Much safer and cheaper.
I have seen secondary expansion
of builders foam in a very expensive
model sat in the sun at the lakeside
resulting in the deck lifting off


Ned
Logged
Smooth seas never made skilful sailors
Up Spirits  Stand fast the Holy Ghost.
http://www.cleethorpesmba.co.uk/

unbuiltnautilus

  • Portsmouth Model Boat Display Team
  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 3,154
  • Location: Portsmouth, England, third rock from the Sun....
Re: Rigidity and Buoyancy
« Reply #6 on: June 26, 2018, 07:44:29 pm »

Also, it weighs next to nothing, while 'expandyfoam' (TM pending,,) surely has a weight distribution issue associated with it. Although on SS Ohio I used buiders pink foam sheets cut and inserted between the frames of the bow and stern sections, then clad with the outer skins. Then again, that is REALLY heavy anyway!!

Logged
Listen politely, nod approvingly, then do what you want, works for me!

grasshopper

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 773
  • Location: Lincolnshire!
    • A1 Hobbies Ltd.
Re: Rigidity and Buoyancy
« Reply #7 on: June 26, 2018, 08:29:40 pm »

I’ve heard some people use those pool 'noodles' cut up and stuffed into any voids..
Logged

unbuiltnautilus

  • Portsmouth Model Boat Display Team
  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 3,154
  • Location: Portsmouth, England, third rock from the Sun....
Re: Rigidity and Buoyancy
« Reply #8 on: June 26, 2018, 09:55:31 pm »

I’ve heard some people use those pool 'noodles' cut up and stuffed into any voids..


Yup, some of the local OMRA boys use it.
Logged
Listen politely, nod approvingly, then do what you want, works for me!
Pages: [1]   Go Up
 

Page created in 0.092 seconds with 22 queries.