1/8" masonite questions??

[Danny]

Masonite comes with a slick side and a rough side. If one was to use this for a top(slick smooth side up), How would you prepare for finish?,(A) for gray primer and then enamel and Also,(B.) For poly or marine varnish?

[goldcoop]

Danny-

I think for enamel finish I would use a "bonding primer"

For Poly or Marine Varnish I think I would use a thinned 1st coat & go from there.

JMO...

Cheers,

Coop

[48Rob]

I'm with Coop, but would also add a bit of "mechanical" bond to both by using 240 grit sandpaper to "break" the surface.

Masonite is a great product, and can last 50+ years outside if properly sealed.
Just make sure ANY exposed part is fully sealed.

If you use Poly, be sure it is rated for outdoor use.
Marine Spar varnish is better able to withstand movement of the surface it is applied too (stretchy...).

Rob

[kennyrayandersen]

I'm with Coop, but would also add a bit of "mechanical" bond to both by using 240 grit sandpaper to "break" the surface.

Masonite is a great product, and can last 50+ years outside if properly sealed.
Just make sure ANY exposed part is fully sealed.

If you use Poly, be sure it is rated for outdoor use.
Marine Spar varnish is better able to withstand movement of the surface it is applied too (stretchy...).

Rob

I would second what Rob said about sealing it. Masonite is a pressed wood product and if it gets wet is just immediately goes to crap. Luan is probably a bit better and it's pretty cheap as well. It may not have as good of a surface to paint, though it is a bit more robust (stronger). It would be interesting to follow a Masonite build over time to see how it would hold up (probably fine if it doesn't get any water on it).

[Larwyn]

I have posted this before, but here it is again

Before I moved ot Kerrville I actually did not have a shop. All my work was outside or under a tarp and storage was under tarps. I had a 4 x 8 foot table which I kept level and covered with a tarp when not in use. All my sheet goods were stored on top of that table. The top of the table was 1/2 inch plywood covered with 1/8" masonite. I had both 1/4" oak and luan as well as some 1/8" oak paneling stacked on the table, some of it for quite some time There were also a few 1/4" masonite templates and such stacked along with the sheet goods. After one particular wet season most of the material on the table under the tarp became and stayed quite damp. Of all the material which steamed there under that tarp, the masonite came through in the best shape. I did not build the Escape Pod from masonite, but from what I have witnessed I do feel that masonite would be a suitable material for the purpose and would not hesitate to use it. The luan came through in okay condition too but it did suffer more warpage and seperation than the masonite. If painted or otherwise sealed they would all work out just fine.

If this involuntary test had preceeded me putting a roof on the Escape Pod there is a good chance that the roof would now be masonite.

[regis101]

I am of the opinion that Masonite is a valuable product.

The most important thing is to seal it.

There are many many houses that have Masonite siding from yesterday to yesteryear. Our 40+ yr old house has 3/8 Masonite siding. It's in good shape for it's age.

I don't know if the formula has changed much over the years but there is a place for it

[Danny]

Danny-

I think for enamel finish I would use a "bonding primer"

For Poly or Marine Varnish I think I would use a thinned 1st coat & go from there.

JMO...

Cheers,

Coop

Good, we have responders.lol.. I am thinking about my next build which I will discuss later. My current tear,I put Luan on the roof, went on just fine however, I used A grade fir on the sides and I hate the red top with the brown fir sides. YUCK or, maybe it is just me. Getting ready to throw some metal over that nasty polycoated luan.....lol.. now, back to the masonite. It would seem if someone wanted to build a cheap tear for someone with little money, this may be an option to knock out a 1/2 inch sided trailer with masonite top and a simple galley and shelf for tv/radio in the cabin. No frills, just a good shaped tear with little outlay. We all tend to overbuild including myself. I have some other designs I have drawn up for a cycle teardrop(oak with a flat oak roof(woodie) hard to explain without seeing it but it would be low profile(42") and a shorty 76 inches long.

[Danny]

so, if prepping for enamel like rustoleum or similar product, We should rough it up with a little 320 grit, then apply a good spray gray primer then the enamel. I suppose a good rolled on oil primer would be just as good. But the spray primers come in the sandable type which allows you to smooth out each prime coat with 320 grit. Any other tips? Thanks to everyone for contributing. I also think masonite has potential as long as it is sealed well and, the edges sealed & protected with molding and some silicone or butyl caulk tape under the aluminum molding extrusion.

[48Rob]

Danny,

320 grit is just a little light for "roughing up".
220 is better...not a lot of difference, but enough.

320-400 is good between coats.

Also, if you are going for varnish, or paint, I would hesitate to use silicone.
Silicone is a great product, and I use it often, but not for something that will need to be recoated or repainted down the road.

Butyl putty under trim is good, it can be removed.

For the areas that you want to use "extra" sealer, clear gutter sealer would be my choice.
I use OSI Micro gutter premium sealer.
The advantage is that it can be removed several years down the road with ease and no damage or residue.
It can be painted over, but I prefer to remove it before recoating.
Silicone doesn't offer those options...

The gutter sealer comes out of the tube pretty thick, but if you heat the tube on the dash of your car with the heater running (or elsewhere) it will become very thin, and thus easy to apply a small bead.
It is very easy to work as well.

I've used it extensively on my Cabin car project.
It has held up very well over the last 4 years with no damage, peeling, looseness, etc.
It stays clear, with no yellowing.
Against the varnish, it is pretty much invisible.
I'm now removing it in preparation for revarnishing, and will reapply when finished.
http://www.osisealants.com/Products.asp ... am-sealant

Rob

[David S]

Danny,

I agree with all of the above,with this added information which may or may not make any difference,
There are 2 types of masonite Tempered and untempered and most suppliers don't ask which you want.I don't know the manufaturing details but the untempered is softer and easy to bend buuuut! it is easy to break in half.The tempered is harder not as asy to bend but in my mind would have to hold up to moisture better.I know 1/4 in comes in both types,I've only ever gotten 1/8in in tempered just because of the break factor.Weve used it as substitute for dry wall in tight arched ceilings, fininsh the corners out with drywall mud, sand and paint looks great.
Good luck the build and as always ,Pictures Please
David,

[alffink]

Just a quick reminder, if you find a nice 50-60 year old TD on the road or stored in an old barn or such, look carefully at the construction.

If the surface had to bend....it was probably masonite, sometimes even if it didn't have to bend.

Now, they had to be repainted or Varnished at least everyother season, to remained sealed, if not it probably isn't around anyway.

Funny isn't, with all of the modern materials and products, in our search for the best or the lightest or a different way of doing things we stumble on something new that turns out to have been the way to do it, back in the begining.

[teardrop_focus]

I like the idea of using masonite... but I have no real experience bending it to the sometimes-tight elipses used in some teardrop trailers.

We know that luan is easier bent perpendicular to it's length rather than it's width... and that kerfing anything will assist in achieving tighter curves... but how tight a curve can 1/8 masonite be bent to before it breaks?

[starleen2]

I used the 1/8 masonite on the first two builds. worked well until I got a leak and the stuff turned into mush!! Masonite will bend around the radius that most teardrops use - but the tempered type will break at a certain point! Now I use 1/8 paneling so I don't have to worry about leaks or sealing both sides. When I'm done - I want to be done. Learned the hard way - and won't look back

[kennyrayandersen]

I used the 1/8 masonite on the first two builds. worked well until I got a leak and the stuff turned into mush!! Masonite will bend around the radius that most teardrops use - but the tempered type will break at a certain point! Now I use 1/8 paneling so I don't have to worry about leaks or sealing both sides. When I'm done - I want to be done. Learned the hard way - and won't look back

That's what I was afraid of -- I couldn't imagine what that stuff would do if it got wet. Maybe it's not, but it seems flimsier than MDF, which is also great for certain stuff (including painting), but if it gets wet it's same thing -- it really goes to crap (plus MDF is pretty heavy since the glue content is high).

[Danny]

[quote="David S"]Danny,

I agree with all of the above,with this added information which may or may not make any difference,
There are 2 types of masonite Tempered and untempered and most suppliers don't ask which you want.I don't know the manufaturing details but the untempered is softer and easy to bend buuuut! it is easy to break in half.The tempered is harder not as asy to bend but in my mind would have to hold up to moisture better.I know 1/4 in comes in both types,I've only ever gotten 1/8in in tempered just because of the break factor.Weve used it as substitute for dry wall in tight arched ceilings, fininsh the corners out with drywall mud, sand and paint looks great.
Good luck the build and as always ,Pictures Please
David,[/quote No build right now,sorry..Just putting some new galvanized on my benroy is all. need to sell some stuff first before any new builds ..I thought it would be good for us to discuss masonite I am going to start a thread on galvanized sheet metal tonight. Galvanized is another overlooked product that is cheap and looks great however there are things a person needs to know. We will discuss it on that thread. Cheers, and thanks for the great input..Danny