Mahogany and Walnut Runabout by Bedford - RADIO

[Bedford]

I started this little project a few years ago with the intent of using up leftover planking and other materials from tall ship builds. I like building R/C and made a 1:8.5 scale Land Rover Defender 90 a while back and this will go on a trailer behind it. I don't "play" with these things much as it is the build that I like. The Defender was scratch built based on a commercially available body and drive train components.

 

I always loved the look of the Riva Aquarama and this is losely based on that boat. I drew the plans myself then bought a set of plans for the Aquarama to make sure the shape of the bow was right.

 

The basic concept was to build plank on frame, with a difference. I was going to build up a three ply hull in situ by laying one layer of 0.6mm limewood (from memory) sheet along the bottom of the hull. Then cut the sheet into short lengths and glue to the first layer at right angles using spray contact adhesive. Then repeat the process in the original direction for the third layer.

 

The sides were to follow the same technique using mahogany sheets.

 

 

[Bedford]

All seemed to go well until well into the sanding and finishing of the lower hull when I noticed that the third layer was delaminating!

 

I peeled it off and resanded the second layer and tried again being very mindful of the instructions on the spray contact adhesive, the same happened again so I removed the new third layer and then sanded the second in preparation for a more conventional wood glue but when I attached the third layer piece by piece it buckled up because of the moisture in the glue.

 

At this point I decided that double planking is a tried and true method of cunstruction so I removed all the offending layers from the bottom of the hull and bought planks to lay, so much for using up excess timbers.

 

I did the sides in the double plank format from the word go because of the dramas I had with the bottom but I decided to opt for walnut outer planks because they have a finer grain thereby having finer edges which fit together much more neatly and the finer grain looks more scale.

[Jim Lad]

Hello Bedford!  How did you sneak in without my seeing you?    Welcome to the forum from down in the Big Smoke!

 

That looks a nice little model you're building.

 

John

[Bedford]

Then began the long drawn out task of spraying and sanding and spraying.....you get the idea.

 

It has come up rather well though.

 

 

[Bedford]

Next came the deck.

 

I am making this up as I go to a degree so it all takes a lot of thinking and a certain amount of trial and error.

 

I want the classic plank with white caulking between so I laid two mahogany planks with a limewood plank on edge between them then tried to trim the limewood back flush with the other planks. This was a dismal failure so I opted for the tried and true cord between deck planks as used on tall ships but with a white cord. It took a while to find a suitable cord but it worked pretty well.

 

 

[Bedford]

Hello Bedford!  How did you sneak in without my seeing you?    Welcome to the forum from down in the Big Smoke!

 

That looks a nice little model you're building.

 

John

Mate, it's been an interesting experience. Learning new ways of doing everything but it seems to be good. I have been sitting here most of the day putting my builds back on the forum, a real shame all was lost but as they say "worse things happen at sea"

 

It is an interesting if troublesome build. I am still not sure how I will line the interior but that will come as will a trailer.

 

Lots of other stuff going on at the moment though so it will take shape slowly.

 

Steve

[michael mott]

Steve that foredeck looks mighty fine, the white caulking turned out really well.

 

Michael

[Bedford]

Thanks Michael, it really is a brain teaser at times but that is half the reason for building it.

 

Steve

[TBlack]

Steve,

Nice work on this which prompts two questions. The cord caulking turned out great, but I didn't quite understand why the limewood approach didn't work for you. Some years ago I was faced with the same issue and used the limewood approach and I don't recall that I had any problems (see photo).

 

The other question that I had is how do you get such a beautiful glass-like finish to the wood?

 

Tom

[Bedford]

Good questions.

 

The deck planks are only 0.6mm thick and the limewood was similar. I was sparing with the glue as I didn't want it getting onto the deck timbers and staining them so I suppose I used less glue that I should have and when it came to trimming the limewood strip back I found that it just kept pulling out below the deck surface.

 

The finish is Cabots Urethane high gloss spray. I went with walnut for the sides for reasons stated earlier and the very fine grain really helps get a very smooth finish, if I had stuck with mahogany I would have needed to sand heaps and use a grain filler before spraying which would not have looked so good. I sand with open coat 400 grit between each coat paying attention to the surface defects it shows up, ie shiny bits need more sanding around till they get dull as well. I sand more and more lightly with each coat while still using the 400 grit.

 

There are about 8 or 10 moderate coats on it.

 

If you have an open grained timber then you need the grain filling sanding sealer which is like a thicker varnish and sands easily, so I am told.

 

Steve

Edited February 19, 2013 by Bedford

[TBlack]

Steve, Thanks for that explanation. Your foredeck is mahogany, so does that mean that you will use a filler up there?

 

TB

[Bedford]

Ah, you don't miss a trick do you?

 

The foredeck is mahogany except for the two centre planks which are walnut, just for a highlight.

 

I found the mahogany planks weren't too bad and since there was a lot of sanding and spraying there and still more to do and the fact that the deck is fairly consistant in its shape and easy to sand evenly it is coming up pretty well without the grain filling sanding sealer but the sheets I was going to use for the sides had massive grain irregularities, combine that with the complex curves of the hull and it would have been impossible to get a decent finish without the sanding sealer.

[TBlack]

I'm just envious of your talent, thanks.

 

TB

[Bedford]

I don't know so much about talent, a bit of education and a lot of perseverance and patience are more what gets that finish. I am still not entirely happy with it though and I think I need a dust free room to do final coats because I always end up with small fine hair like dust in the finish but I will find somewhere suitable to do a final coat soon or maybe just use 1200 grit wet&dry to get rid of the dust.

 

Steve