Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length.

[Neil]

thanks Arrow but just looked and Sheffield insulations nearest is 70 miles away......think I'll stick to wicks 5 miles down the road.


cheers for the other info.


neil.

[Bowwave]

I believe Ron Horabin perfected a similar build process   25years ago   using foam between each frame   and coating the foam with plaster , sanding down and casting  in GRP .
Bowwave

[Neil]

 


thanks dave.

[Ron Rees]

Hi Neil,


I too am an exponent of the 'Foam' building method as can be seen from some of my articles in MB mag. The best foam I have found is Blue Polyurethane foam and I order this from Balsa Cabin or Technology supplies. It is a very stable closed cell structure and  originally used for insulating commercial freezers and fridge units in large supermarkets like Lidl, Sainsburys etc.


I use single part foaming Polyurethane glue from Screwfix (same as Gorilla but cheaper) to build up layers of foam.
This foam sands very easily to a nice fine finish by hand, do not try power sanders at the latter stages of shaping as the surface can get hot and it will tear patches out of the carving or leave darker, rock hard streaks.


This foam will also react with Fiberglass resins so some protection from the car body filler is essential. Epoxy resins are fine. I have used the PVA soaked paper tape method several times but now give the plug a few coats of Dulux Vinyl Matt emulsion which is easier and cheap. It can also be rubbed down carefully if you leave the emulsion to dry thoroughly, you can then go over it with car body filler to get your glass smooth finish before laying up the Master mould as normal.


Some of the yellowish roofing panels from builders merchants are OK but are more crumbly, though you can often find sizeable offcuts in skips. The Pink foam is OK too but not as dense as the blue which is now used a lot for CAD/CAM prototype product modelling and so on. (This was the subject I taught Engineering and Design students at Degree level before I retired)


I actually make the whole hulls out of the foam now, finishing them initially with nylon cloth or ladies tights and Epoxy resin or Ronseal Floor Varnish (PVA based). They are very light and unsinkable and will take quite a knock with little or no damage. Just carve out the locations for fixing the hardware.
I do not recommend foam masters for Vacuum forming though as the resins used for the finish coats will come away from the foam sub base if any excess heat, like in Vac forming is used.


Average time to carve a 30 inch hull is about an hour or so, so it is a very quick method.


Hope this helps..........Happy boating.


RON.

[Neil]

Ron...........that is a very concise and superb description and probably the best I have heard from anyone, and many thanks for your input and your superb knowledge.


I appreciate it very much and all the downfalls that one might encounter on the way. I shall now google these two suppliers and get something going for the new year.............


I thought my luck was in the other day when I passed a spot coming out of Fleetwood where someone had flytipped a load of blue foam, so like the womble I am, I turned back and went to load it into my car..............sadly only to find that it was about 25mm thick but glued to 20mm ply wood, so abandoned the thought.


thanks again Ron, for taking the time to give a blow by blow of the stuff......greatly appreciated.....blue foam it is.


neil.

[Big Ada]

When I was building my 19 foot long Big Boat I used Blue foam to float the centre sections on, I got it from Travis Perkins the Builders Merchants, The bloke in the Yard said there were some packing pieces around the back and to help myself, just the job. 

Len.

[DavieTait]

Neil find a local commercial builder , they use this foam in industrial units for insulation and most of these companies will happily let you take all the offcuts you can carry as it costs them money to have them disposed of

[Neil]

cheers guys...........i'll go on the hunt. after the new year....everyone has packed up now.

[Big Ada]

New years Resolution  =  Never pass a Skip without checking for Stuff.
And be nice and ask if you can take, before you take it.

[T33cno]

Hopefully you can see this.
https://www.facebook.com/photo.php?fbid=2206511616033019&set=pcb.1567192376669244&type=3&theater

[Neil]

Hopefully you can see this.
https://www.facebook.com/photo.php?fbid=2206511616033019&set=pcb.1567192376669244&type=3&theater

 

[Neil]

having looked at that aberration,  .I think that method would take more time in cleaning up the expanding ffoam than it would a plank on frame build...........not for me am glad to say..........couldn't stand the mess it causes to begin with..........my work shop in in a big enough mess as it is, lol.

[steamboatmodel]

Back when I was doing fast electric and gas racing models we experimented with the expanding foam. Found out that you can not pour it into a restricted space, as once it expands to fill that space any extra liquid gets trapped in it and with applied heat (hot summer day) start to expand again, forcing the original foam as well as the hull sides out of its way. I have found that the blue builders insolation foam works good.
Gerald.

[ballastanksian]

I agree about pink and blue foam. I have a Pre dreadnought on the go with the hull built in pink foam which I intend to hollow out and furnish. Ron gave me many tips about the tecnhiques in using insulation foams.

You do make a lot of shavings and some dust, but a sharp carving knife and fully extended snap-off craft knives keep dust to a minimum especialy once you get your 'Carving mojo' on.

I have coated my hull in a mix of Blue emulsion and PVA. The former shows where the latter has not covered fully. I will then try the tights and EZEkote method also shown by Ron to clad it in before hollowing and detailing.

Good luck with your build Nick, I look forward to seeing your progress :O)

[Neil]

cheers, neil.

[ballastanksian]

Sorry 

[red181]

as mentioned, depron is a close cell foam, cuts with a sharp knife, sands very easy. You can use epoxy resin, uhu por, or foam friendly cyno. You can paint it etc.


American variation is blue dollar tree foam, I understand this is all floor insulation. We use this in aero modelling as its light, and can be covered, and cheap. Its waterproof, we use it for water-planes to great effect. I know a few people who have constructed boats from this.


hope that helps!


Paul

[Neil]

cheers all that have contributed...........shall go in search for some in the new year.