Model Boat Mayhem

Technical, Techniques, Hints, and Tips => Painting, Finishing and Care. => Topic started by: dodgy geezer on August 04, 2009, 10:28:27 am

Title: Strengthening and protecting balsa
Post by: dodgy geezer on August 04, 2009, 10:28:27 am
Todays question is about balsa covering.....

I am trying to provide a resource to revive the old balsa KK EeZeBILT range for young kids (see the links section if you want o visit the site!)

KK EeZeBilts were made of balsa, which is a brilliant material for cutting and sticking, but a poor one for resisting handling and water. So, once one was built, we used to cover it in sanding sealer to protect it, inside and out. Sanding sealer is still available, but hard to find and, I suspect, expensive. Is there a more modern varnish or filler which will do the same job and can be bought at B&Q?

I had thought of the polyurethane range, but I understand that they can form a skin over the wood, then split and let water in? What I need is a 'filler' which really soaks into the balsa....
Title: Re: Strengthening and protecting balsa
Post by: mook on August 04, 2009, 10:30:56 am
sanding sealer is still available from B&Q  O0
Title: Re: Strengthening and protecting balsa
Post by: dodgy geezer on August 04, 2009, 11:37:12 am
Really? Apologies for wasting your time! I had just asumed that anything that was used in the 1960s must have been superceded by a mixture of health&safety legislation and brand new up-to-the-minute computer driven automated paint mixers.

Off I go to buy whatever passes for a pint pot nowadays....
Title: Re: Strengthening and protecting balsa
Post by: tigertiger on August 04, 2009, 12:22:30 pm
People also soak balsa in thin CA which can increase strength 3 fold.
Beware of fumes though. CA liquid seems to have a lot of them.
Title: Re: Strengthening and protecting balsa
Post by: Martin (Admin) on August 04, 2009, 12:24:47 pm
On a recommendation, I tried some Ronseal Wet Rot Wood Hardener ... I wasn't impressed.

(http://www.screwfix.com/sfd/i/cat/24/p44724_x.jpg)
http://www.screwfix.com/search.do;jsessionid=B5FFGGAL4XSUUCSTHZPCFEY?_dyncharset=UTF-8&fh_search=wood+hardener&searchbutton.x=0&searchbutton.y=0&searchbutton=submit

Title: Re: Strengthening and protecting balsa
Post by: andrewh on August 04, 2009, 12:40:35 pm
DG,

I use ronseal quick-drying acrylic varnish now for pretty much alll the things that dope, sanding sealer and banana oil used to do
 It does, er, exactly what it sez on the tin, and once hardened is (as near as makes no matter waterproof). 

I keep hearing about a floor sealing product which is better than the underwater biro, but have never tried it myself

Americans swear by spray Krylon
andrew
Title: Re: Strengthening and protecting balsa
Post by: dodgy geezer on August 04, 2009, 12:48:11 pm
On a recommendation, I tried some Ronseal Wet Rot Wood Hardener ... I wasn't impressed.

http://www.screwfix.com/search.do;jsessionid=B5FFGGAL4XSUUCSTHZPCFEY?_dyncharset=UTF-8&fh_search=wood+hardener&searchbutton.x=0&searchbutton.y=0&searchbutton=submit



Martin, what was the issue with it? It sounds like the sort of thing that would be really useful for soft balsa...
Title: Re: Strengthening and protecting balsa
Post by: Martin (Admin) on August 04, 2009, 01:07:58 pm
It's just didn't seem to soak in, it just painted on the surface.
It smells like cellulose dope.
Title: Re: Strengthening and protecting balsa
Post by: madrob on August 04, 2009, 01:19:54 pm
What about that g4 pond sealer i keep hearing about
Title: Re: Strengthening and protecting balsa
Post by: dodgy geezer on August 04, 2009, 01:26:04 pm
Hmm... I seem to be the proud posessor of a lot of little bits of variable density balsa at the moment - I made the mistake of going to a modelling shop and selecting some sheets by examining the top 6". What looked like medium hard turned out to vary amazingly down the length of the sheet, giving me formers which are crisp on one side and crumbly on the other.

I thought of using some of the rubbish in a controlled test with several protective coatings to see what the best/most cost-effective covering was. So are there any other suggestions for things I might try?
Title: Re: Strengthening and protecting balsa
Post by: Martin (Admin) on August 04, 2009, 03:33:27 pm
I'll give it 24 hours and I'll test tomorrow.
Title: Re: Strengthening and protecting balsa
Post by: Shipmate60 on August 04, 2009, 03:41:18 pm
Have you considered painting the bare balsa with Polyester Resin, makes it waterproof and gives a hard external coating.

Bob
Title: Re: Strengthening and protecting balsa
Post by: dreadnought72 on August 04, 2009, 04:04:31 pm
Listen to madrob, and bung some g4 on it! It's fabulous. Martin, can you do a test of that "aussi"?

Andy
Title: Re: Strengthening and protecting balsa
Post by: Circlip on August 04, 2009, 06:53:39 pm
Golden Oldie DG, Tissue paper and Dope, I'll send you a pikky.

   Regards  Ian.
Title: Re: Strengthening and protecting balsa
Post by: dodgy geezer on August 04, 2009, 07:37:42 pm
I'll give it 24 hours and I'll test tomorrow.

Martin

It would be interesting to know how deep into the wood the treatment goes. Will you be able to view a cross section?
Title: Re: Strengthening and protecting balsa
Post by: dodgy geezer on August 08, 2009, 12:14:35 pm
sanding sealer is still available from B&Q  O0

Just tried a big B&Q today. They've never heard of it, it's not on their computer, and they directed me to the sandpaper section....
Title: Re: Strengthening and protecting balsa
Post by: bosun on August 08, 2009, 02:12:33 pm
Hy DG I have a 500 ml can of Sanding Sealer I bought mail order from Blackburn Models about a year ago.
I am sure some one from around that way can give you the address. Failing that, the manufacturer on the tin is,,,H.Marcel Guest Ltd,  Collyhurst Road, Manchester M40 7RU  telephone   0161 205 7631 .
Hope this helps.
Bosun
Title: Re: Strengthening and protecting balsa
Post by: Shipmate60 on August 08, 2009, 02:45:27 pm
In B & Q interior door sealer IS Sanding Sealer.

Bob
Title: Re: Strengthening and protecting balsa
Post by: biggles1 on August 08, 2009, 09:47:30 pm
Hi Dodgy Just been using Sanding Sealer on my Triton got it from local model shop no problem.its dist. by J Perkins who still supply bannana oil (none shrinking dope) and and shrinking dope.It is manufactured for Perkins  by HMG Paints Manchester tel 0161 2057631. Dont now what part of London you live but if its south try Avicraft Chatterton Road Bromley Kent. I have also seen it in craft and dolls house shops.The floor polish mentioned is jOHNSONS KLEER from your local supermarket  some moddellers are using it instead of dope on tissue coverd planes shrinks and dopes in one process and no smell.    Dave   
Title: Re: Strengthening and protecting balsa
Post by: dodgy geezer on August 11, 2009, 11:40:35 pm
Hi Dodgy Just been using Sanding Sealer on my Triton got it from local model shop no problem.its dist. by J Perkins who still supply bannana oil (none shrinking dope) and and shrinking dope.It is manufactured for Perkins  by HMG Paints Manchester tel 0161 2057631. Dont now what part of London you live but if its south try Avicraft Chatterton Road Bromley Kent. I have also seen it in craft and dolls house shops.The floor polish mentioned is jOHNSONS KLEER from your local supermarket  some moddellers are using it instead of dope on tissue coverd planes shrinks and dopes in one process and no smell.    Dave   

I'm north. Sorry - I haven;t been paying attention to making anything - been too busy wondering about motors. Will we get any build pictures of your Triton? Have you thought about radio? What motor are you using....
Title: Re: Strengthening and protecting balsa
Post by: dodgy geezer on August 11, 2009, 11:57:59 pm
Hy DG I have a 500 ml can of Sanding Sealer I bought mail order from Blackburn Models about a year ago.
I am sure some one from around that way can give you the address. Failing that, the manufacturer on the tin is,,,H.Marcel Guest Ltd,  Collyhurst Road, Manchester M40 7RU  telephone   0161 205 7631 .
Hope this helps.
Bosun

Thanks, bosun and shipmate, I found the URL OK - they sell 0.5lt for £9+post. B&Q do an 'International Universal Primer Sealer' for £21 (2.5lt)...
Title: Re: Strengthening and protecting balsa
Post by: tigertiger on August 14, 2009, 02:45:17 am
***Topic Split***
New topic - Actions cassette motor and speed controller:  http://www.modelboatmayhem.co.uk/forum/index.php?topic=19073.0

Bosun's reply to Dodgygeezer
Title: Re: Strengthening and protecting balsa
Post by: Bee on September 04, 2009, 10:09:15 pm
The B&Q sealer (International is the B7Q own brand) is just dilute PVA glue. Works quite well and no fumes but is not as good as the solvent based sealers.