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gottatrotter · 12-12-2011, 07:13 AM

I ordered floor repair bolts from vintage trailer supply, but now I'm not sure how to use them. They appear to have a drill bit on the tip. My question is, having removed all the elevator bolts, am I trying to run these screws through the new floor into the existing holes in the frame, or do they self drill a new hole in the frame. Not sure how on earth I will hit the existing hole....didn't think to mark that on my template. They did not come with a nut, like the existing elevator bolt, should I put one on anyway. this is a shell on, belly on, partial rear replacement. I need to attach at the c channel too, but Im concerned that these screws are to long for that, and may puncture through my belly. they may be designed only for the attachment to the frame, I'm not sure. Any help is much appreciated

Wabbiteer · 12-12-2011, 07:53 AM

You're bound to get fiveteen responses with eleventeen different flavors & layers of suggestions...

Bypass the original threaded lugs remaining after you've removed the old bolts. Stay at least 1/2-inch from the vacant hole when driving the new screws. You might make a pencil tick mark on the floor next to the old bolt-holes, or write down the distances from the shell lining etc. to help keep away from them. Being able to drill a few trial pilot holes and lifting up the floor boards (if you can) to visually check if your alignments are correct could be a good thing only if you can get the board back to that original position. Try to keep away from the sheet metal edges by at least 1/2 the diameter of the screw, a full diameter spacing is stronger but sometimes there just isn't room.

Self-drilling bolt/screws like a higher RPM if you're just shooting them without a pilot hole. Think 3600-4000 versus 1800 of the average drill. Just let up on the trigger in time to keep from burying the screw head too deep or pulling/stripping the threads loose.

Doing a pilot hole to make sure you're hitting metal helps - make sure the bore you make is 'true', any lean your drill has the screws are bound to folow. #12-24 self-tapping machine screws like the ones sold for plywood replacement can use UP TO 5/32" drill bit to make the pilot hole, and as its self-drilling an 1/8" bit would still work. I used 5/32" and they all worked famously, even as 1/2" of snow built up on the floor around me as I hustled to get the shell landed, none stripped even if I was overly motivated so-to-speak.

The trailer floor screws have cutter wings, small steel blades right before the threaded shank. Those are made to snap off once they've touched the backing metal but I always snap them off with a pair of wire cutters, I imagine they are meant for thicker housing style subfloors, the 1", 1-1/4" and more thicknesses that would stagger screw driving from friction.

Good luck and take your time - don't be afraid to walk away from it for a few minutes and start back refreshed, once we fatigue is when errors creep in

perryg114 · 12-12-2011, 08:00 AM

I drilled and tapped new 1/4-20 holes in my floor and frame and counter sunk the elevator bolt with a spade bit to make a pocket for the bolt head. Those frame members are pretty hard at least on my 81. I tried putting in some stainless steel sheet metal screws with a pilot hole and it stripped the screw threads.

Perry

gottatrotter · 12-12-2011, 08:18 AM

thanks for the great info. So, just to be clear, these floor repair screws are not designed for the c channel attachment, just for attachment to the frame. So, what to use at the c channel. all elevator bolts were cut out (no notching for me). however, since I didn't drop the belly completely (just up the center) I cant place a nut on the bottom side. considering some kind of anchor, but the clearance between the floor and belly is very limited at those edges. an abundance of wood screws perhaps?

perryg114 · 12-12-2011, 08:41 AM

Drill and tap the frame members. The threads will be in the frame so the frame is your nut. You have to have bolts with phillips or slot heads on them. The C-Channel bolts are just 1/4"-20 standard hex head bolts with nuts on the back side. I used stainless steel on mine. Use large washers to distribute the load. I put a piece of angle iron at the back of mine to distribute the load. These are what I found but phillips head would have been better. The bolts that VTS sells are for older trailers that have a C-channel frame not a modern box frame. You also have to have the skins off so you can get to the bottom of the bolts to put nuts on them.

McMaster-Carr

Perry

gottatrotter · 12-12-2011, 09:00 AM

oh no,.........I so didn't want to remove the skin, but can't think of any way to anchor those c channels. wow this project just keeps getting bigger and bigger. so a hollow wall anchor is a bad idea? how about 50 hollow wall anchors? has nobody done this with the skin on?

Wabbiteer · 12-12-2011, 09:34 AM

You can* drill the frame rail belly skin rivets and loosen the outside wraps from the lower edge to access the through-bolt ends without too much trauma or drama.... may be a lesson in 'don't start none, won't be none' once you see the conditions in there though...

perryg114 · 12-12-2011, 09:39 AM

You really want to remove the skins and remove all the wet, rat invested pink crap in there. Usually the pink stuff rots the frame or at least rusts it. Best to clean all the crap out and POR15 the frame. Most folks put some sort of rigid insulation back in but no insulation is much better than wet fiberglass.

Perry

gottatrotter · 12-12-2011, 10:01 AM

cleaned all that out when I removed the old floor....found a snake skin....ew. used styrofoam cut neatly to shape with new fiberglass on top. gonna have to tear that out to access bottom of bolts. should have planned better. thanks for all the help. what size bolts am I picking up to do this?

gottatrotter · 12-12-2011, 10:22 AM

thanks perry...1/4" 20 hex....got it

perryg114 · 12-12-2011, 10:27 AM

Do you have some photos of what you are working on?

Perry

jbib · 12-12-2011, 10:41 AM

At one point you said you dropped the center section of belly skin. If so, you can drill up from underneath through the original holes to locate them, and then insert your self-tapping screws from the top. I used a 12" long 1/8 inch drill bit and was able to flex it enough to get a reasonably vertical hole.

barts · 12-12-2011, 10:46 AM

When I fixed the rear end separation on the Tin Pickle, I fixed the floor piecemeal as well. I used 8-12" wide blocks of 3/4" plywood, glued with polyurethane & fastened with laminating screws, to tie the replacement pieces into the remaining good sections. The rear cross member was cleaned, painted and I drilled up from the bottom w/ a long drill bit through the new stainless steel angle plate into the existing holes in the C channel.. The C channel is now fastened every 8" or so to the rear cross member with 1/4" stainless bolts w/ stainless locknuts; the bolts in the rear corners are 3/8" stainless.

The stainless angle is riveted to the skin every 1.25" or so to match the existing rivet patterns all across the back; I also sistered in a piece of 5003H .040" or so aluminum just behind the existing skin as the bottom portion was quite corroded.

The entire rear assembly is now rock solid, needless to say.

In general, I find the practice of bending over bolts to prevent them from loosening to be a very shoddy practice; lock nuts are a far better solution to this problem.

On older trailers, the frame is far too thin to tap for 1/4-20 NC; good practice says a minimum of three threads, and that would be .150 thick - far more than the frame is on the Tin Pickle, anyway.

- Bart

perryg114 · 12-12-2011, 11:52 AM

I think you can get by with less than .150" thick metal to get good threads. All your doing is holding down some plywood not building the space shuttle. When you tap threads in thin metal the tap extrudes some metal and gives you a little more thickness. At the back, you need nuts because you are making a structural connection. I added angle to the frame and made some more outriggers out of angle so both pieces of plywood would have their own supports.

Perry

gottatrotter · 12-12-2011, 01:44 PM

attached picture of the section I'm working on. Its the attachment of the rounded corners at the c channel that's giving me trouble. I think perry is right. I'm going to have to drop the rest of the belly to get to the underside of those bolts. my airstream dream is turning into an airstream scream

perryg114 · 12-12-2011, 07:53 PM

Welcome to the club. An Airstream is like an onion. There is always another layer of tears under the first one. I would bite the bullet and take my time doing it right. You have an older trailer with open frame channels. You can put nuts on the back side of the beams or drill and tap them. I would remove the skins and inspect the frame for rust through then POR15 it. Coat the new wood with something like urathane or epoxie to help water proof it. I don't know how the structure at the back works on the old ones. Mine does not have a rear compartment like yours does.

Perry

gottatrotter · 12-13-2011, 06:50 AM

i believe you're right. removing the skin today so i can properly bolt the curved edge. Frame looks remarkably good even has most of original black paint. Primed it anyway. Thanks so much for convincing me not to mess it up. if its worth doing, its worth doing right.

perryg114 · 12-13-2011, 07:09 AM

Good luck with it. I would paint the rest of the old floor to seal it and also seal off any bad smells etc. My floor looked bad and was stained with all sorts of stuff. I used some porch and floor and we are using that as a floor till I get all the leaks stopped and decide on the next step for renovation.

Perry

gottatrotter · 12-13-2011, 10:01 AM

good luck. I hope i sealed my last leak last weekend (vent pipe). Supposed to rain tomorrow so we'll find out. the floor paint is a great idea. Don't want to have to replace flooring ever again.....what a nightmare. planning to recover the floor with wood laminate. I know, "the weight, the weight". But I'm planning to minimize the load by not running it under any beds or seating. Plus it's going to look great. All I wanted to do when I bought her was decorate and make her cute. I had no idea I would need to do so much maintenance first. my next step after this floor is the missing front window. not having luck finding one so I may have to fabricate a temporary one with some extrusion.....eeek
thanks for all the help

anna

perryg114 · 12-13-2011, 10:34 AM

You may find that the bolts that hook the frame rails to the rear corners are bigger than the ones on the rear cross member. I would use the size that came out. You can get small quanities of stainless steel bolts at Lowe's or Home Depot. I think mine were 5/16-18 at the frame attach points.

Perry