Minwax Wood Hardener Paper Use Test


Cardstock Model designer
Feb 1, 2006
Nikiski, Alaska
Bought a couple of cans of Minwax Wood Hardener, thinking it might be something to use on cardstock.
Wood Hardener.jpg
Yesterday was warm enough (54 deg F) to do the test out in my garage. Didn't want to breath the fumes as the stuff smells and looks like the liquid cement used to make plastic models from back in the 70's.
Need a way to improve the strength of the internal PSI tube inside of my air launch-able rockets. The big ones weigh enough that just using cardstock for the PSI tube isn't enough. With the higher pressures need to launch their weight, the PSI tube goes Ca-Bluey...

The testing was done to check out a few things that follow:
1) Will a Aleenes Turbo Tacky glue joint still hold up?
2) How does it affect the cardstock?
3) Can you use Aleenes glue once the hardener has been applied?
4) How much weight does it add?
5) How hard does it make the paper/cardstock?
6) Does it affect printed inkjet ink on the parts?

Used a small metal handle brush (disposable/cheap) to apply it to a sample PSI section and a plain piece of 20lb Bond copier paper. It did glue the brush hairs together, just like lacquer or any paint/stain.

Applied 3-coats yesterday afternoon around 4pm. Coats were applied per the instructions: Keep adding coats while the other coats are still wet to ensure deep penetration. I did not cover the whole PSI tube, wanted to see the difference between treated and non-treated areas.

Brought it inside today after letting it sit in the garage last night (cooled down to 37 deg F).

Initial look finds that the application on the PSI tube is favorable.

1) Aleenes held up nicely, the double layer of cardstock at the glue joint looks great, photo shows the internal end view. You can clearly see how it soaked in, except the one spot where it didn't make it through the bottom layer. Rest of glue joint is saturated all the way to the top. Did not apply as much to the end to see what would happen.
2 Internal Coverage on Glue Joint.JPG

2) Gave the cardstock and paper a shiny transparent look.
1 Shiny.JPG

3) Closeup of the Bond paper to show how it bonded the paper fibers. Note you can see the text through the paper as well.
4 Plain Paper Closeup.JPG

4) Forgot to weigh the PSI tube before applying, so will need to test the weight gain in the future.

5) Where the cardstock is saturated, it is harder than the non-applied areas. The closeup of the paper also shows how the paper edge appears to be bonded between fibers.

6) When applying to the paper, checked out the backside and could clearly see that the first coat went completely through, little beads of hardener could be seen. After a second coat the beads formed a new layer that covered the applied area completely.

7) Cardstock and paper are both stiffer/harder than the non-applied areas.

8) Did not affect the ink at all.

9) Added benefit, seems to act like a glue. Touched the brush to a finger and then pressed to another finger, it did stick the fingers together.

10) Acetone can be used for cleanup.

11) HEALTH WARNING: Only use with good ventilation. Will buy a 1/2 face respirator and OV (organic vapor) filter when I use it next! Warning on back says not to inhale-death can result.

12) Did not test to see if Aleenes will stick to it yet. If I can will try a test today, if can get the time to do so.

All in all very happy with the test results so far! Clearly it bonded the paper fibers together, paper is still flexible, but can tell that it is a little stiffer than the non-coated area. Doesn't appear to be much weight gain.

Looks like I will have to build another 10ft Tall 1/32 scale Saturn V Rocket to test a heavy rocket launch!

BTW-Bought my hardener at Home Depot in the paint stain area. Think I paid around $11 that includes tax for two cans.

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Reactions: Rhaven Blaack

Rhaven Blaack

Staff member
Jun 12, 2009
Thank you for the tutorial. It is very informative.
I have been looking at a hardener and protective coating for some of the models that I want to build for handling. I will continue to follow this thread and see how this works.


Staff member
Apr 6, 2013
I had a friend who built rockets so big, he had to call people to get permits to launch them. I have attached a .pdf from NASA about making your own tubes. You can see from their method, that the changing thickness, and switching to a Resin, instead of white glue will give you a quite sturdy rocket tube. My friends were 12" inches in diameter, and around 18' feet tall. We've lost touch, after he shut down his hobby shop, but I am sure he is still doing it. :)

http://www.redarrowhobbies.com/paper_body_tubes.htm Good selection of tubes , best prices.