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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Carpentry Questions >> Softwood - used outside. Trailer rebuild https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1391307339 Message started by JohnD on Feb 2^nd, 2014, 2:15am

Title: Softwood - used outside. Trailer rebuild
Post by JohnD on Feb 2^nd, 2014, 2:15am

I have an old Rice half ton open cargo trailer that I am very fond of, and am using in my building project. Its planking has finally rotted after only 43 years of use and abuse.

I want to keep it as original as possible, so have bought some floorboarding (same as original) to replace the sides - the base will be treated scaffold board, a bit thicker than what was there originally.

1. I will obviously put a few coats of paint to preserve it, but should I treat the timber first and if so with what? It needs to be something I can paint over. I can see lots of timber treatments out there but don't know which ones can be over painted.

2. And should I stand the cut planks in some form of treatment before use to stop the cut ends soaking up water once fitted? (Varnish??) I know most planking used on this sort of job rots from the ends in.

3. Is it worth going over the finished paint job in varnish to protect it?

A lot of questions over a simple job but I want another 41 years out of it. By that time I might just have built my extension (!) and in any case I will be will be nearly 100 and it will be someone elses problem!!

Thanks

John D
.

Title: Re: Softwood - used outside. Trailer rebuild
Post by woodsmith on Feb 2^nd, 2014, 9:39am

You could use a clear five star preservative and soak the timber in it before standing it up to dry which will help or you could take the timber to have it pressure treated would would better protect it. Another option is to use Accoya which is a specially treated softwood which should easily last 25 year s but it isn't cheap. I don't think varnishing over paint will work, you would actually be better off using a breathable paint, it's water getting trapped under the paint which causes most of the damage. Another option would be to use Osmao Country Colours paint, it's linseed oil based and does not form a distinct coating like traditional paint. I don't know how durable it would be as regard abrasion but it would be very easy to keep on top of maintenance with this sort of finish.

As for the end grain, I have tried rubbing polyurethane adhesive into the end as it expands and fills up the capillaries but this would be counterproductive if the wood got wet further along the board.

Keith

Title: Re: Softwood - used outside. Trailer rebuild
Post by JohnD on Feb 2^nd, 2014, 11:33pm

I will go for the 5 star preservative - I have found a cuprinol wood preservative which sounds ideal.

It helps that I am not in hurry for this - I have a few evenings off andcan afford to take my time and get it right.

Thanks very much for the advice Keith

John D

Title: Re: Softwood - used outside. Trailer rebuild
Post by Natedog on Jul 1^st, 2014, 12:35am

I did the floor and headboard of my big trailer with cheap pine floorboards from the local builders merchant. They had the ends soaked in creosote before fitting, and then 4 coats of creosote on each side. Every autumn I give it another coat of creosote before the really bad weather sets in. I'd rather go for something that soaks into the wood, as paint will flake off when it gets old.

I'm about to replace the floor in my little trailer too. Currently it's just 1/2" sterling board, and the last load of logs I collected went thru it. But hey, it was cheap and has done me 6 years with no protection on it at all. This time I'm going to use 2 layers of pallet slats and creosote them.

Title: Re: Softwood - used outside. Trailer rebuild
Post by londonman on Jul 2^nd, 2014, 7:16pm

This from a heritage restoration website.

Linseed paints last for many years, and just need freshening up every 5 years or so with a thin coat of linseed oil. The paint never cracks, and the wood never rots, because no moisture is trapped into it.

DO NOT ever use plastic paints - acrylic paints - modern 'breathable' paints... The big paint companies will tell you their paints are 'breathable' - their paint chemists tell me they are anything but... Judge for yourself - put a nice coat of Dulux gloss all over your windows and see how long it is before it all cracks and flakes, rotting the timber underneath by trapping moisture.. It's not breathable and never will be - its made with plastic!