Anyone used "Wood Hardener" in Rocket build?

[kjkcolorado]

Talking with someone at a launch this weekend they mentioned a product called "wood hardener" saying they were thinking about using it to strengthen body tubes and wood fins during construction of their high powered rockets. I clarified that he wasn't talking about a wood filler product. He said he picked some up at an ACE hardware. On my way home I stopped at my local ACE to look and found the Minwax product he was referring to. The directions are aimed at cleaning up wood that is rotting, then applying this to the remaining wood to harden and protect it. Is anyone familiar with this and what are your thoughts on using it for fins, body tubes, etc?

 

[JAL3]

I use it but not as a hardener. The hardening qualities are marginal. I suppose it helps some, but by itself, I don't consider it worth the effort.

I use it as a solvent for Bondo Spot and Glazing putty. A 50/50 mixture by volume is prepared and brushed on for sealing balsa or other wood grain. I also fill spirals. It dries fast and is easy to sand. It produces lots of annoying red dust but I like the results better than any other sealing method I've found. If it makes the balsa a bit harder as well, that's a bonus.

 

[Marc_G]

Sure. Do a search for "Minwax" and you will probably get hits. I've used it to harden balsa but was not overly impressed... doesn't harden as hard as CA and takes a long time to cure all the way.

I did find that you can mix bondo/3M spot putty into it and that mix makes a nice filler. I called it teamwork filler. I used it for a while with good results.

Then I found that sealing/hardening with CA, then shortly after painting on some spot putty (thinned with lacquer thinner if desired) can be ready for sanding in hours rather than the days or weeks needed when using wood hardener.

Others have found the hardener works well when soaked in then given weeks/months to fully cure but I don't have such patience!

 

[luke strawwalker]

Haven't used it but read quite a bit from folks who have...

Basically it seems a mixed bag... some say it's worth it, some say it's a waste of time and money-- ESPECIALLY TIME.

The folks that have had the most luck with it seem to let the nosecone and components literally soak in the stuff for days or weeks to allow it to penetrate deeply into the wood... Of course this requires you to dig out the kit from your stash and set up all the parts to soak in the stuff or repeatedly apply it over a long period of time, and wait to actually construct the kit until the parts have had ample time to soak the stuff up, and hope nothing gets lost in the meantime. The other issue is, how much good does it really do??

You can probably get about 95% of the same level of benefit by simply using "water-thin" CA (Hobby Lobby sells a terrific CA for this purpose, in a pink labeled bottle (different colors for different thicknesses) to saturate the wood grain of the nosecones or tube ends during construction. The CA readily soaks into the wood grain and hardens, basically turning the balsa into a "composite material" consisting of the wood fibers and the CA 'resin'... same thing with paper parts like tubes or paper transitions. It really strengthens them up, and takes VERY little time to do (BUT, it DOES require EXCELLENT ventilation, as the CA fumes are heap big powerful and about like tear gas-- apply the CA OUTSIDE with a CROSS BREEZE, NOT with the wind at your back (which will cause turbulence and whiff them fumes up into your face as you work) or with the wind in your face (which will blow the fumes directly from what your working on straight back into your face-- a cross-breeze will carry them away from you).

I wouldn't rely on this methodology much to help you in HPR... sure it'll help SOME, but it's not gonna suddenly make a 0.021 wall Estes type LPR tube as strong as a 0.040 thick wall "HPR" tube... IOW if you REALLY need the extra strength, just go with a thicker-wall tube to begin with and call it good...

Later and good luck with your projects! OL JR

 

[kjkcolorado]

Thanks for the feedback. Glad you all included comparisons with CA. I forgot to specifically ask that question, but wood hardener vs CA was part of my initial curiosity. Sounds like my time and money would be better spent learning to work with fiberglass as I find myself wanting to build larger, higher powered rockets.