Don't know the Sadolin stuff, I use Billing Boats stains meself, BUT whatever you use, esp on balsa, apply a coupla coats
first. Then at least one or two coats
of clear satin varnish
; e.g. from Lord Nelson range from Holland. THEN AND ONLY then, apply your stain til you get the depth of colour you want.
After that seal with matt, satin
or gloss varnish
according to taste😉 That's the way I did my Sea Scout 'Jessica' renovation, see blog on this site for results!!! Coupla sample pics attached. The whole process is described in the Blog.
Otherwise the balsa will soak up all your stain and still not look right 🤔
A 'preserver' as such is not normally necessary if the wood is properly treated inside and out; sealer
, stain, varnish
etc! Or just EzeKote resin inside. Stain no needed inside of course.
Good luck and above all have fun with your endeavours. 👍
Keep us 'up to date' ('on the running' as my German friends would say; 'auf den Laufenden'!) 😁
Cheers, Doug 😎
PS I like Danish Blue meself 😁😁
On the other hand; I wouldn't have used balsa for speedboat deck in the first place. I use a close grained marine ply 0,8 or 1.0mm. Takes the stain better and looks more realistic. Balsa is too coarse grained for stain and varnish
on scale speedboats. Thick coat of paint ... OK. On the cabin roof and after deck (which I had to renew) I used 1.5mm mahogany veneer.
If I had to do it again I would use a close grained 0.8mm marine ply (birch or pear) and cherry stain (also Billing) as I used on 'Jessica's deck.