Question About Bolting Wood Together for a Loft

[ArcticRSXS]

Hey guys, i built a loft (See Pics below). After a while the bolts loosen up. I re-tighten them but im basically just pulling the bolts deeper into the wood each time i do this. If i tighten them to the point right before they dig into the wood more the loft is still kinda shaky. Do i need to use a different kind of washer/bolts or do i need to use screws or is there something fundamentally wrong with my design?

thanks for any help

Pic right before completion (When its Down)
http://img378.imageshack.us/img378/6245/10kw.jpg

Completed Loft (When its swung up)
http://img378.imageshack.us/img378/6027/26mu.jpg

These are the Bolts, Nuts, and Washers that loosen up over time.
http://img378.imageshack.us/img378/1452/34br.jpg
http://img378.imageshack.us/img378/640/44nd.jpg

[KenTheHandyMan]

For some reason the pictures aren't coming up, but given your explanation, I would say you have used a very soft wood and should simply use larger diameter washers. It might not even be out of line to purchase some nice metal plates and drill through those (again, I can't see the pix so I might be off), plates sometimes add a nice touch if done right.

[ArcticRSXS]

Thanks for the reply and sorry about the pics. I put the link addresses up so hopefully that works.

I beleive the wood i used is pine. I have washers on the side of the nut, but i dont have one under the bolt head on the other side. From what you said i figure thats my problem.

However, since the bottom of carriage bolts are square i have one more question concern. Should i just get a washer thats big enough to go over the square part of ths shaft? Sorry if this is a silly question. This is the first thing ive ever built and doing that seems wierd for some reason.

thanks for all the help so far.

[GMW]

Would it be possible with the desin to add a small triangle brace? Such as a piece of plywood cut about 8" on each leg. That would strengthen that joint quite a bit. If not a couple of screws or liquid nail will help keep it from loosening up.

[KenTheHandyMan]

OK, now that I can see what we're dealing with Let me just say that we definately have a structural issue here. There is too much tension on those 'joints' where the bolts are holding two pieces together. That tension will cause them to dig into the wood.

I would suggest that you use some sort of X-bracing on the legs (at least on the sides) to remove that tension from the bolted areas. The nicest looking and strongest way to do that would be to route out channels in the brace and leg pieces, but if you're not able to do that, you can attach them to the sides, like you did with the horizontal members. The only thing with that is that you can only do half of the X on one side and half on the other, which will make your sides somewhat fat! Those leg ends need supported though. I can draw you a picture if my suggestion is unclear. Just let me know.

[slickshift]

Originally Posted by ArcticRSXS

These are the Bolts, Nuts, and Washers that loosen up over time.
http://img378.imageshack.us/img378/1452/34br.jpg
http://img378.imageshack.us/img378/640/44nd.jpg

Looks about right for soft pine crate furniture
Store-bought or home-made

You could use larger washers, that'd help
The larger washers could defeat the purpose of the "square" on the carriage bolts (keep from spinning while tightening), so you may need to replace those with more traditional bolts do you can hold them when you tighten them up

You do need more bracing also
X-type, or ladder, even an H-type would probably do it

[ArcticRSXS]

thanks Ken and Slick,

I get what you guys are saying about the need for more bracing. The only problem i have is i have limited access to tools at school and i also have to take the LSAT Oct 1 so i dont have much time right now to cut wood and drill holes. If there arent any other options i will just have to fix it after the LSAT.

However, i was wondering if instead of wood i could use some kind of metal L bracket or somehting of the sort. Even a straight metal bracket put on an angle at each corner as in the pic below:
http://img98.imageshack.us/img98/9485/57fm.jpg

Then i could just screw the brackets in and i wouldnt have to worry about measuring more wood and drilling holes in it.

Sorry if this idea sucks. This loft is the first thing Ive ever built so i really do appreciate all the info you guys are providing me b/c i have no idea what im doing.

edit...when i say metal bracket i think i mean metal brace

[slickshift]

That'll help, but not enough
You really need something from leg to leg
It's just too spread out
It's gotta be at least 39" one way and 54" the other right?

[KenTheHandyMan]

Just to let you know, the L Brace thing is what you see when someone has built a table like this and found that the legs weren't supported so they tried to beef it up with the braces. :D Don't get me wrong, those metal braces have their place, but they were not meant to perform that type of structural strength. You'll find that they get loosened just as bad. If you really don't want to put a lot of time into it, at least screw a 2x4 from leg to leg about half way up. That will give it some strength and help the bolts to not loosen so much. X-bracing prevents racking, but H style will at least keep the legs from buckling.

Measure the distance of the 2x's at the top and you should be able to use that measurement.

[Teetorbilt]

I see a few design flaws, but that aside, why not just loosen the joints and put some glue (TiteBond II) or some epoxy in the joint. You will need a saw for disassembly but it will cure your current problem.

[KenTheHandyMan]

Gorilla Glue!

[Teetorbilt]

Ken, how good is this stuff? I have bought 2 small bottles to build race boats and they both went bad prior to construction. Unopened shelf life here is only a few months. Opened shelf life for TiteBond is about a year or better. TiteBond is also water cleanup and the wood has always been the weak point upon forced seperation. Epoxies can penetrate to 1/8", where does the Gorilla Glue fall into this?

[slickshift]

Originally Posted by Teetorbilt

Ken, how good is this stuff? I have bought 2 small bottles to build race boats and they both went bad prior to construction. Unopened shelf life here is only a few months. Opened shelf life for TiteBond is about a year or better. TiteBond is also water cleanup and the wood has always been the weak point upon forced seperation. Epoxies can penetrate to 1/8", where does the Gorilla Glue fall into this?

It has it's uses, Teeterbilt
I always have some GG in one of my tool bags
But also a few different TiteBonds
I refer to the TiteBonds for way more apps.

The GG expands....a lot
Sometimes this can be helpful in old furniture repair (think of a loose fitting chair leg that must be glued, the expansion helps)

It also expands alot, and this can be a problem
The squeeze out is mostly better scraped of after cure
Yes, this will affect the finish
Great for repairing a futon or bunk bed
You don't want it anywhere near some cabinets that you just built

I don't mean to say it's only good for old furniture repair, I'm just tryng to illustrate the differences

In fact the GG is very good at gluing dissimilar materials
As I said, I always have some

Your un-opened shelf life is only a few months?
I realize you are a bit warmer than me, but aside from the temps, our working environments are similar
I'm on the corner of river and ocean, and could throw rocks into 6 marinas from my work shed (OK two of them I'd have the NFL scouts out here if I could, but still, they are pretty close)
I've been getting longer out of opened bottles

But I do only by the smallest ones because they do go bad before they get used up

[ArcticRSXS]

I think im going to go with the glue method along with putting washers under the bold head.

I was wondering if titebond or gorilla glue is better for what i need to do. Also if i should get titebond which kind should i get. I looked at the website and there are a bunch of different kinds.

[KenTheHandyMan]

Diddo on the GG. The stuff does have its applications, but not on anything that you are concerned about the finish, unless sanding and painting are the goal. I was looking into it once to see if it was a suitable epoxy replacement for building boats. The GG people say that it is not designed for 'below the waterline' applications, but that there are several boats out there held together with the stuff. It is strong and is nice if you're glueing things that aren't necessarily wood, like slick says. But it also does expand a lot. You'll put it on and think you're OK (Whew! I didn't put too much on.) Then go inside for a drink and come back outside with foam all over your newly built solid oak childs chair...don't ask.

I think your shelf life is a bit shortlived on the GG. I know once it's opened, you better use it though. I've actually seen it foam up inside the bottle. If you need to open it, a chop saw will be required.

Anyhow, Titebond II is waterproof (above the waterline, like as in a birdhouse) and to be honest, if you're glueing wood, Titebond is about the best thing to hold it together, outside of marine grade epoxy. So if there is any dampness, you're good with TB II.