Newbie Looking Leaning Towards a Foamie (My Question Thread)

[KCStudly]

So are you going to pocket hole screw (Kregg) the subframe together?

Plan your frame with the xmbrs running long over the sides of the trailer and the long boards capping the ends of these, all on edge (just like you are probably envisioning). Then you lay 1x2's down flat on top of the trailer frame side rails... stringers, if you will. Cut your xmbrs to length, clamp all of them together at the same time and lay them out over the trailer frame and stringers. Mark where they intersect and notch the bottom of the xmbrs so they sit down over the stringers. Make all of the notches at once while they are still clamped together so they are all in a line and there are no measuring mistakes. Spread your xmbrs out and Kregg down from the vertical faces above the notches so that the Kregg screws will run into the stringers. Once assembled you can bolt thru the stringers and trailer frame in between the xmbrs where it is wide and flat and is still part of the subframe.

[jseyfert3]

So are you going to pocket hole screw (Kregg) the subframe together?

Plan your frame with the xmbrs running long over the sides of the trailer and the long boards capping the ends of these, all on edge (just like you are probably envisioning). Then you lay 1x2's down flat on top of the trailer frame side rails... stringers, if you will. Cut your xmbrs to length, clamp all of them together at the same time and lay them out over the trailer frame and stringers. Mark where they intersect and notch the bottom of the xmbrs so they sit down over the stringers. Make all of the notches at once while they are still clamped together so they are all in a line and there are no measuring mistakes. Spread your xmbrs out and Kregg down from the vertical faces above the notches so that the Kregg screws will run into the stringers. Once assembled you can bolt thru the stringers and trailer frame in between the xmbrs where it is wide and flat and is still part of the subframe.

How you describe the frame is how I was was envisioning it. And the stringers/attachment method make perfect sense, thank you.

[jseyfert3]

Here is a frame make of 1x4s (3/4" x 3 3/4"). 8' long, 5' 4" wide. I'm going to start modeling up a TD so I get a better feel of how it will work. I wonder if someone has modeled a HF trailer already that I can use...

Frame by jseyfert3, on Flickr

[jseyfert3]

I wonder if someone has modeled a HF trailer already that I can use...

Of course there was. That made it easy.

So, this is what you described, correct? Is a 1x2 laid flat enough to pocket screw into? 3/4" doesn't seem to have a lot to hold on too, then again there'd be at least ten screws or so holding the frame to the stringers.

HF Trailer and wood subframe by jseyfert3, on Flickr, on Flickr

Note there is no center crossbeam on the trailer, as those are now in the side rails to facilitate moving the axle back. I'll either replace with a 2x4 or similar or just leave it be, the side rails will be stiffer, plus the TD itself will help with holding the sides together. Do you recommend attaching the 1x4's to the trailer crossbeams, considering they can be right on top as in the Sketchup model, or will attaching the notched 1x4's to the stringers over the side rails be sufficient? If so, do you have a recommendation on the best/easiest way to do so?

For the floor, I figure I could fit the same 2" foam I'm using to build it into the spaces between the 1x4's. How thick do I need to go for ply/OSB? There is no planned walking on the floor (no room), just a queen mattress for sleeping.

Hope you don't mind all my questions, I have a tendency to overbuild, which causes me to think that what's probably quite sufficient does not look strong enough.

[GPW]

JS, I dunno’ about that ? Looks like it puts all the stress on those little stringers eh .. I was thinking about some simple blocking that would reinforce the cross-members in the bolt areas ...no stringers necessary ... and basically , you could drop a bolt through in any location you wanted.. Easy !!!

[KCStudly]

Tight joints glued and screwed with the trailer attachment bolts close to the xmbrs (not in the middles of the bays where the stringers might have a tendency to flex more) and I think it would be fine.

GPW's scabbed doubler plates idea would also work fine, so long as the wood scabs (fish plates in steel parlance) are long enough. I would go at least twice the height in length on either side of the breach, glue and use several screws thru all three boards on either side, and don't put the screws too close to any edge. Not sure I like the idea of using such long bolts.

Another option w/o the stringers would be to use a small 1x block to double each xmbr just where they cross the side rails and use hurricane ties to screw the wood frame to the steel frame (wood screws into wood and self tapping TEk screws... predrilled... into the steel). Might be more thrifty than larger bolts; lots of redundancy of fasteners in a light weight package. Strong and light. No complex wood working or awkward drilling.

[GPW]

Hurricane ties... that’s Brilliant KC !!! We used a whole bunch of those for the House and Studio build and the city building inspector said he wanted to see a nail in every hole ... makes sense...

[jseyfert3]

Hurricane ties... that’s Brilliant KC !!! We used a whole bunch of those for the House and Studio build and the city building inspector said he wanted to see a nail in every hole ... makes sense...

I agree, makes sense, seems quite easy. No pocket drilling, no stringers, no cutting notches to fit over the stringers. A bit of drilling to drill 5 holes per hurricane tie, let's see, 5*10 = 40 holes! But they are small holes, so it should go a lot faster then drilling the 7/16" holes for moving the axle back.

Any issues with small metal screws like that due to rust? I don't forsee a lot of winter camping but I figure I'll go once or twice. Road salt gets everywhere and rusts the sh** out of cars.

[GPW]

JS, wherever we can now , we use SS screws... The others rusted pretty quick ...

[KCStudly]

If you're worried about rust, just drill thru the hurricane tie and all and use 1/4-20 SS bolts with nylon insert self locking nuts on the other side. You could get really crazy, position everything, drill out the holes, remove the floor, and paint inside the holes, too, but... like I said... that would be crazy.

Have a look at these stainless steel TEK screws. Again, you will want to pre-drill (the self drillers are really only good for thin sheet metal), and you will want to check to confirm what size you will need, but I would go a little bigger, rather than smaller. The little ones can snap off pretty easy when driving them in thicker material. If you have any unused pieces from your trailer kit that are the same thickness as the rails, do a test to see what size pilot hole works best, and what clutch setting to run your driver at so that you don't snap any off in the holes. Drilling straight also helps avoid snapping screws off.

A #10 screw might be okay, too.

[jseyfert3]

So it sounds like SS screws should be good? If for some reason they start getting too rusted, or the holes they are in do, I can always drill and change them to SS bolts down the road. But I mainly wasn't thinking of SS screws when I asked the question.

If you have any unused pieces from your trailer kit that are the same thickness as the rails, do a test to see what size pilot hole works best, and what clutch setting to run your driver at so that you don't snap any off in the holes.

I actually don't have a drill with a clutch, yet. I had a HF corded drill, and a Dewalt 12V Max impact driver I got along with two batteries and a charger from HD for free (right place at the right time). So after you posted that, I looked around for the 3/8" Dewalt 12V Max drill/driver. Snagged one on ebay with no charger or batteries for $30, shipping included. So now I will have a drill with a clutch. I wanted to get that drill anyway, this was just a bump to encourage the purchase. Corded drills are great for stuff like drilling the metal frame of my trailer, but a lightweight, cordless drill with clutch will come in handy for various homeowner projects. Oh, and I do have two 2" pieces of cross-beam the same thickness as the side rails that I cut off, so those should work great for testing screws.

Right now I'm leaning towards the hurricane ties with SS screws, as you have suggested. Sounds pretty easy. Need to finish fixing my miter saw when I get home so the Permatex sleeve retaining compound can set before I'm ready to cut the cross-beams. (the key on the gear/shaft interface sheared about two weeks ago when I was making some sawhorses)

And that makes me think of another question. What are "common boards"? Pine? Seem to be the cheapest 1x4's at HD, only $2.22 for an 8' one, or $15.54 to do my entire sub-frame. Not the smoothest finish but nobody's going to see them. Then what, 1/2" OSB to go on top for my floor? 3/8"?

HD Common Board by jseyfert3, on Flickr

Am I asking too many questions?

[Mary C]

You are doing fine, I used bolts through the OSB and go through the side rails in the extra bolt holes already in them. It is only held on with 6 bolts but ya ain't gonna move them. Before you bolt anything in place I used O Henry roofing white stuff In a gallon can in the roofing section It is like a very thick white paint. It will seal the wood underside of the trailer. don't get the kind with aluminum in it. It will rub off on everything. Or you can get the black tar stuff , My suggestion is that you paint the protectant on and let it dry before you bolt it down. Lying on your back and painting either one ain't fun.

Mary C.

[KCStudly]

I would step up to the select pine, if it was me. Easier to find straight boards, and a lot fewer knots, rough edges and whatnot.

If budget is a big concern, the knotty stuff would be okay; just be aware of the issues.

I'm a detail freak and have found that the more accurate that I can keep each piece, the less "out of true" things tend to get down stream in the build. If you compromise and pick a bunch of noodle shaped wood, you may have to deal with it throughout the rest of the build.

On the other hand, many people have built plenty of decent campers using all manner of different materials, so, as Popeye said, "Ya pays yer money and ya takes yer choice".

[jseyfert3]

Browsed Menard's today, I find it to be fun and relaxing to just look around stores like that if I'm not busy. Snapped a couple pictures, my favorite way to take notes on stuff to look at later.

1x4 - 8' Standard, $1.98 by jseyfert3, on Flickr


1x4 - 8' Quality, $2.22 by jseyfert3, on Flickr

The select was really nice. No knots, sanded smooth, not as warped. But 5x the cost of the knotty stuff, at $9.59 a board vs $1.98.

1x4 - 8' Select, $9.59 by jseyfert3, on Flickr

I was pretty surprised to see a board this warped in the select, I sure as hell wouldn't pay $10 for that. And it sure wasn't the only warped/bent select piece either.

$10 Select - Warped much? by jseyfert3, on Flickr

I would step up to the select pine, if it was me. Easier to find straight boards, and a lot fewer knots, rough edges and whatnot.

If budget is a big concern, the knotty stuff would be okay; just be aware of the issues.

I'm a detail freak and have found that the more accurate that I can keep each piece, the less "out of true" things tend to get down stream in the build. If you compromise and pick a bunch of noodle shaped wood, you may have to deal with it throughout the rest of the build.

Here's the thing though, besides straighter pieces, is there other difference besides smooth/no knots? Because the way I'm planning, nobody will see any of the wood, canvas will come off the foam and wrap over the edge of the wood. As you can see above, I'm looking at approx $14 vs $70 to jump from the basic to the select. I wouldn't buy noodle shaped wood, I understand that can cause numerous issues, but if I look through for 7 relatively strait pieces, I think I should be good for building the frame. And the select wasn't even as straight as I figured it'd be for 5x the cost. Certainly less, but still there...definitely what I would want for boards that would be seen, though.

OSB for the floor, what minimum thickness do I need? I was thinking floor framing every 2', so it'd have to span a 2' gap. Nothing planned between gaps but 2" foam cut to fit between the 1x4's. The floor framing would run perpendicular to the long dimension of the OSB. Prices are $8.47 for the 7/16", $11.95 for the 1/2", and $15.97 for the 5/8". Not as concerned about the price as the weight, although it is another factor, can get almost two sheets of the 7/16" for the price of one sheet of 5/8".

You said Hurricane ties. Found another tie I thought may work, then realized when I brought one home for testing it would not work that great in this application, as it would only work if slid so low it would only screw into the bottom of the 1x4 and the frame.

Other Rafter Bracket by jseyfert3, on Flickr

Holding up a hurricane tie to see how it would work. Should work great. At the end of the rail I should be able to put it in a vise and hammer the side over 90°, allowing the end board to be at the very front/rear of the trailer. If you don't get what I'm saying, imaging sliding the tie left until the 2x4 lines up with the end of the side rail, then bending the left side of the tie that's now overhanding the edge away from the screen. The screwhole by my thumb then would screw into the rail on the back or front of the trailer, and not the side rail the rest of the screws screw into. There is a little gap between the 2x4 (should be the thinkness of two stacked 1x4's), I could shim that with a part of a paint stir stick or leave it, I'm guessing it'll close up just fine when I screw in from both sides.

Hurricane Tie by jseyfert3, on Flickr

Interesting, unrelated sign I ran across while I was there. Instead of a solid 6', I found that a lot of the 6' boards were sold as 71-72". Is this another cheapening measure, like what they went from a real 2" x 4" to 1.5" x 3.5", or do people not need a board in a true 6'? I don't understand why being cut from a longer material means it varies up to an inch in length, of course it's cut from a longer material, all boards are...

Can't be an Exact 6'? by jseyfert3, on Flickr

[KCStudly]

Look at the grain of the select boards, it is long and relatively straight compared to the Std. Some of the Std boards don't even appear to have grain; they're all plain white and knots.

To me this means that the select boards are stronger and will hold their shape better. No knots means nothing to fall out later, and no weak spots at critical stress points, like where your xmbrs cross your side frame rails and cantilever out. No issues with hitting a knot right where you want to run a screw thru your hurricane ties, or join two boards together. If you consider that you might have to buy half again as many boards so that you can cull out the ones that don't work well in your cut schedule due to knot placement, and the better integrity of the select boards, making another trip to the store when you can't find one in your pile that doesn't have a knot in the wrong spot, it starts to make more sense.

But if budget is your ultimate concern, it can still be done on the cheap. Heck, you could spend the difference on a finger jointing tool and splice your wood together from recycled pallets (sarcasm).

It all depends on what is acceptable to you. I'm just trying to suggest that sometimes penny wise is pound foolish. Just my perspective.

On the other hand, if I ever build another, I won't be so worried about using high grade materials. I am there now and am doing that. Too early to tell if it is truly worth it. There is definitely a sliding scale of thrift vs. build speed vs. build quality vs. potential longevity.

2 ft spans are pretty generous, and that is about what I have in my floor (maybe closer to 18 inches?). I only have 3/16 thick skins (5 mm) but have a piece of scrap 1/2 ply on rosin paper laid down during the build so I can walk on it. Once the roof goes on and the mattress is down there won't be so much point loading (will only be crawling or laying down) so it will be fine. The foam is, however, fully glued to both the upper and lower skins, so there is a great deal of modular strength built in. Just stuffing chunks of foam under your floor won't give the same strength as a torsion box.

If you want to dance on it, I wouldn't go less than the 1/2 inch, and with larger spans and a single top skin only, you might want the 5/8. Just an opinion from what I have read here, really; not hard fact. $.02

Seems like I'm not really offering hard solutions to your questions, but I hope it is at least helping you to decide which way you want to go.