Torsion box question. Now progress reports.

[Jim O'Dell]

Man, this is going slower than usual! I got the sheet of MDF Friday on the way home from work. Lost a couple hours this am going to the Arlington shelter to look at a reported Irish Setter, but it was a mix, so had to pass. Man that is SOOO hard to do.
Started cutting the MDF about noon. After lunch and a visit from a friend from Florida, and her father, who lives south of Dallas, I went back to work. Let me tell you. DON'T use your table saw for your assembly table!!!! I got everything flat and ready, found some cuts I failed to make. AARRGGHHHH!! Take it a part, make the cuts, put it back together, and guess what???? Yep, more cuts I failed to make. I wasn't about to take things apart again, so I put my dad's ole RAS to use...didn't even check to see how far out of adjustment it was. But it did fine. In fact, I don't think I could get it that well tuned if I tried! So I have the first one dry fitted except for the top skin, and ready to put together. But I'll wait for that until tomorrow. Hope I have enough glue!! Jim.

[Jim O'Dell]

Thanks Steve.
You know, I don't do well watching glue dry! I get restless, I want to undo clamps and go to the next step, even if I mess the next step up! At least I'm doing something!
Well, my little tankless compressor won't shoot the 18 guage brads in at an angle, so I have to shoot them straight in, which changes how I wanted to do this. I guess I'll bondo and sand the holes before laminating the top and edges. Right now the glue is drying on the splice of what will be either the top or bottom of the first box. I wanted to shoot the brads in at an angle so I could have a top that has no holes to fill, but that won't happen. And man, do I need more clamps!!! Well, it will just make me go slower and hopefully catch my mistakes before they are past the point of saving!
Hope everyone is having a good Sunday! Jim.

[Jim O'Dell]

Ok, here it is. I took a couple pictures along the way. This first shot shows the set-up with the temporary extension to the left of the saw to get 10' of flat surface. The second shows the patch for the joint in the top skins. I hope this is what you were talking about Charlie. This picture is a closer look at the end opposite of the patch. #4 is a blurry picture of the whole thing after one skin and the grid is glued and braded. And the final one is of the finished unit. My sides didn't come out as smooth as I wanted, but they will be ok. I'm pretty happy with the top surface. It's not perfectly flat according to my 5' cheapy straight edge, but not bad. I didn't check it again after I knocked off the high spots at the seams and did a light sanding all over, so it may have improved, or not.

OK, the new question...Do I need to prep the MDF for the laminate? Or just put the adhesive directly to the raw wood?
I'll do the next box next weekend. Probably prep the assembly surface again for it during the week. Maybe this one won't take as long? Assembly took about 5 hours today. Thanks for looking and all the comments and help! Jim.

[Jim O'Dell]

Gee, Steve, that sounds like sanding!! I scraped the seam, and sanded with ROS before the last picture, I just didn't take the straight edge back to it. One evening this week I'll do the bondo "thang" to the indentions from the brad nailer, and go back with the ROS.
Thanks for the heads up on the adhesive and the raw MDF. I just wasn't sure if it might need some sanding sealer on it first or not. Jim.

[Norman Hitt]

Jim, I agree with Steve, and on MDF, only sand "LIGHTLY", just enough to knock off any glaze on the surface, (and truly, if you're using regular, "NOT WATERBASED" contact cement, I don't think you even need to sand unless there are rough spots).

Now, for the smoothest, AND easiest way to laminate the two together, lay the laminate upside down on the box and use a SHORT napped paint roller, and pour the laminate glue on the laminate, and then spread it and roll it out (all with the paint roller). Roll it til it is all an even thickness and starts getting tacky and make the last few strokes lengthwise, just like you were painting, and then move on down to the next area. When you are finished with the laminate, slide it off the box and do the same procedure on the box. When the glue is barely tacky, then lay dowels across the box and flip the laminate over and slide it onto the dowels, then align it and start working it down from the center toward each end, and this will help eliminate any bubbles/air pockets. I not only roll mine, but also use a flat block of wood and a hammer and pound it down all over, (Overkill, maybe, but it sure works for me.

Now another tip, you don't have to even clean up the roller, just put it into a heavy ziplock bag, (roller frame and all), and pour about a half cup of the thinner in it and stick it in a bucket out of the way, and when you want to use it for the other top, the cement will soften it and it will work again.

I've tried many methods but this one works the best of all. The most important part, being to use the roller to spread it out instead of trying to spread it with something else and then try to even it out with a roller, and oh yes, don't be bashful when pouring out the cement, as you want get it spread over a large area quickly before it starts to dry.

Good Luck, hope this helps.

[Jim O'Dell]

Thanks Norman. I think you anticipated my next question before I did! I have watched laminate being installed on MDF before, and I knew about getting a J-roller for it, but I don't remember how he did the adhesive unless he sprayed it. Probably did spray, they always had that going for gluing fabric, but I just don't remember. I also knew about the wood strips. Doubt that I'll invest in dowels for this, although I do have a couple out there...might just be enough for the job. Thanks for the insights!! Jim.

[Norman Hitt]

So Jim, is the laminate done yet, or have you been screwing aroung with sprinklers, roofing or tending DOGS?

You gotta get with the program now, 'cause we all want to know how it turned out. (since you've been kinda quiet for a few days, I am concerned that you got your shirt tail glued between the laminate and the MDF, and can't get through the door to get out of the shop).

[Jim O'Dell]

So Jim, is the laminate done yet, or have you been screwing aroung with sprinklers, roofing or tending DOGS?

You gotta get with the program now, 'cause we all want to know how it turned out. (since you've been kinda quiet for a few days, I am concerned that you got your shirt tail glued between the laminate and the MDF, and can't get through the door to get out of the shop).

No Norman, that's next weekends doings! I built one box last Sunday, got everything prepped for the second one on Wed. eve, and I'll put it together either this afternoon or tomorrow. I'm at work this am.
I took off a little early yesterday afternoon to get a new filter for the sprinkler system, lost pressure and it was 2 years old and very clogged up. Stopped by HD and looked for laminate...none except the pre built counter tops. They used to have it at their old store, but the new ones evidently don't. I'm taking off next Friday for several things, and will locate the laminate then and work on it.
You should know by now that I don't get in a hurry about anything, well, except growing old. Jim.

[Norman Hitt]

No Norman, Stopped by HD and looked for laminate...none except the pre built counter tops. They used to have it at their old store, but the new ones evidently don't.

They don't carry it out here at the HD store anymore either, but the Lowes over in Midland does, (and probably does in your area too).

I'm taking off next Friday for several things, and will locate the laminate then and work on it. You should know by now that I don't get in a hurry about anything, well, except growing old. Jim.

Boy, don't even mention being slow, I used to be pretty quick with all my projects, but I'm slower'n running Molases in -20* weather anymore. (My mind still "Thinks It", but the body just refuses to cooperate).

[Jim O'Dell]

Yes, I stopped in the HD and Lowes in Weatherford after getting my hair cut yesterday, and Lowes does have a few sheets of either 3X8 or 4X8 material...white and a couple of multicolor. I was hoping for blue or preferrably light grey. So I'll hit the professional place on Friday after doing some other things I need to take care of.
I did assemble the second unit yesterday afternoon/evening. Will get out today and bondo the 3 zillion holes from the brad nailer, then decide what to do about straightening out the edges to get them flat. Have a good Sunday! Jim.