Epoxy or Other Filler or Other Something

Hi, All. I need to run some screws (say No. 8) into blind holes to hold a section of slider track. I have 1/4" of fiberglas to go into, and about 1/2" open space behind it. Nuts are out of the question as are butterfly bolts. This is for attaching a hatch slider, so I don't have much clearance on top either (would need to use flat head screws (these are inside the slider). A couple thoughts. I don't think pop rivets would fit, and the residual "heads" would be too big. I was wondering if there is some filler or blend into which I could run self-tapping screws or tap for machine screws. I suppose If could do helicoils, but the thought of bigger holes is somewhat scary. Are any of the expanding fillers any good? Any sage advice (or any other kind) gratefully accepted. Cheers Charlie

They make flat head pop rivets. http://www.boltdepot.com/Blind_rivets_Flat_head_Stainless_steel_-_Stainless_steel_mandrel.aspx Also check out rivnuts http://www.rivetnuts.com/ They also come in contersunk versions http://www.cheapestrivnuts.com/countersunk-head-ribbed/111-6mm-countersunk-ribbed-steel-rivnut.html From: "Husar, Charlie [USA] (ASE)" <hu… [at] bah.com> To: "CAL Yahoo (Ca… [at] yahoogroups.com)" <Ca… [at] yahoogroups.com> Sent: Monday, April 22, 2013 7:35 PM Subject: [Cal_Boats] Epoxy or Other Filler or Other Something Hi, All. I need to run some screws (say No. 8) into blind holes to hold a section of slider track. I have 1/4" of fiberglas to go into, and about 1/2" open space behind it. Nuts are out of the question as are butterfly bolts. This is for attaching a hatch slider, so I don't have much clearance on top either (would need to use flat head screws (these are inside the slider). A couple thoughts. I don't think pop rivets would fit, and the residual "heads" would be too big. I was wondering if there is some filler or blend into which I could run self-tapping screws or tap for machine screws. I suppose If could do helicoils, but the thought of bigger holes is somewhat scary. Are any of the expanding fillers any good? Any sage advice (or any other kind) gratefully accepted. Cheers Charlie

Charlie, I've had some luck with riv-nuts. It is sort of like a rivet that is threaded. I've bedded them in with epoxy to help keep them from spinning, but again it's been hit and miss. It worked well for some deck fittings, but not so well for lazarette hinges. McMaster Carr has a good selection that you can look at. Greg From: "Husar, Charlie [USA] (ASE)" <hu… [at] bah.com> To: "CAL Yahoo (Ca… [at] yahoogroups.com)" <Ca… [at] yahoogroups.com> Sent: Monday, April 22, 2013 7:35 PM Subject: [Cal_Boats] Epoxy or Other Filler or Other Something Hi, All. I need to run some screws (say No. 8) into blind holes to hold a section of slider track. I have 1/4" of fiberglas to go into, and about 1/2" open space behind it. Nuts are out of the question as are butterfly bolts. This is for attaching a hatch slider, so I don't have much clearance on top either (would need to use flat head screws (these are inside the slider). A couple thoughts. I don't think pop rivets would fit, and the residual "heads" would be too big. I was wondering if there is some filler or blend into which I could run self-tapping screws or tap for machine screws. I suppose If could do helicoils, but the thought of bigger holes is somewhat scary. Are any of the expanding fillers any good? Any sage advice (or any other kind) gratefully accepted. Cheers Charlie

I have thickened epoxy into a peanut butter consistency with west 404 then drilled and tapped it. It doesn't sound like the fastener has any significant loads on it. I don't see why that wouldn't work here. Think about trapped air though. Either drill a small hole out the backside and fill till epoxy is coming out of small hole, or use a syringe or ziplock baggy to put the epoxy on the farside of the hole so it's forced to come forward, displacing air as it goes. Make sure you continue push the syringe in as you pull it out of the hole though, again, so you don't trap air.

On 4/22/2013 10:35 PM, Husar, Charlie [USA] (ASE) wrote: > Hi, All. I need to run some screws (say No. 8) into blind holes to hold a section of slider track. I have 1/4" of fiberglas to go into, and about 1/2" open space behind it. Nuts are out of the question as are butterfly bolts. This is for attaching a hatch slider, so I don't have much clearance on top either (would need to use flat head screws (these are inside the slider). A couple thoughts. > > I don't think pop rivets would fit, and the residual "heads" would be too big. > > I was wondering if there is some filler or blend into which I could run self-tapping screws or tap for machine screws. The Gougeon Brothers have done a lot of work on "bonded fasteners" (I think that's what they call it). Basically, it's machine screws or bolts in epoxy. They have data on shear loads, tension loads, etc. Gougeon Bros. do not recommend anything without testing and data. They describe removal (apply head to the fastener) and other operations. As usual, they have a whole array of filler materials with different engineering characteristics. If by "slider track" you mean the kind of track a sliding hatch runs on, then you don't need much strength in tension or compression nor much more in shear. Use some sort of backing plate on a toothpick to hold the epoxy, fill the holes, drill out for stainless "wood screws" (the constant-diameter screw that pass for wood screws in stainless these days). Chris Campbell >

I bet you could just drill and tap the 1/4" fiberglass for this. If you want more bedding for the screws I would just syringe some thickened west systems (thicken with that silica additive) to make the area in the 1/2" space act as an additional reinforcing backing, then drill and tap the whole thing. If you could use some anodized 3/16 aluminum pop rivets that would work very well...maybe even 1/8" rivets especially if they'll be several of them supporting the track. But if there are several fasteners for the track, I think just drilling and tapping will work fine, 1/4" fiberglass is pretty substantial. If this was for a rail for a jib block, I'd want to do the west systems hardware supporting backing procedure as described above. Jerry of Shpritz. From: Chris Campbell <cc… [at] lsnm.org> To: Ca… [at] yahoogroups.com Sent: Tuesday, April 23, 2013 10:48 AM Subject: Re: [Cal_Boats] Epoxy or Other Filler or Other Something On 4/22/2013 10:35 PM, Husar, Charlie [USA] (ASE) wrote: > Hi, All. I need to run some screws (say No. 8) into blind holes to hold a section of slider track. I have 1/4" of fiberglas to go into, and about 1/2" open space behind it. Nuts are out of the question as are butterfly bolts. This is for attaching a hatch slider, so I don't have much clearance on top either (would need to use flat head screws (these are inside the slider). A couple thoughts. > > I don't think pop rivets would fit, and the residual "heads" would be too big. > > I was wondering if there is some filler or blend into which I could run self-tapping screws or tap for machine screws. The Gougeon Brothers have done a lot of work on "bonded fasteners" (I think that's what they call it). Basically, it's machine screws or bolts in epoxy. They have data on shear loads, tension loads, etc. Gougeon Bros. do not recommend anything without testing and data. They describe removal (apply head to the fastener) and other operations. As usual, they have a whole array of filler materials with different engineering characteristics. If by "slider track" you mean the kind of track a sliding hatch runs on, then you don't need much strength in tension or compression nor much more in shear. Use some sort of backing plate on a toothpick to hold the epoxy, fill the holes, drill out for stainless "wood screws" (the constant-diameter screw that pass for wood screws in stainless these days). Chris Campbell >

Is anyone out there? I haven't gotten any Cal Groups mail in a Coon's age. Did the whole fleet sink, or am I skunked? Jerry of Shpritz. On Wednesday, April 24, 2013 7:05 AM, Gerald Sobel <so… [at] yahoo.com> wrote: > > > >I bet you could just drill and tap the 1/4" fiberglass for this. If you want more bedding for the screws I would just syringe some thickened west systems (thicken with that silica additive) to make the area in the 1/2" space act as an additional reinforcing backing, then drill and tap the whole thing. If you could use some anodized 3/16 aluminum pop rivets that would work very well...maybe even 1/8" rivets especially if they'll be several of them supporting the track. But if there are several fasteners for the track, I think just drilling and tapping will work fine, 1/4" fiberglass is pretty substantial. >If this was for a rail for a jib block, I'd want to do the west systems hardware supporting backing procedure as described above. > >Jerry of Shpritz. > > >________________________________ > From: Chris Campbell <cc… [at] lsnm.org> >To: Ca… [at] yahoogroups.com >Sent: Tuesday, April 23, 2013 10:48 AM >Subject: Re: [Cal_Boats] Epoxy or Other Filler or Other Something > > > > >On 4/22/2013 10:35 PM, Husar, Charlie [USA] (ASE) wrote: >> Hi, All. I need to run some screws (say No. 8) into blind holes to hold a section of slider track. I have 1/4" of fiberglas to go into, and about 1/2" open space behind it. Nuts are out of the question as are butterfly bolts. This is for attaching a hatch slider, so I don't have much clearance on top either (would need to use flat head screws (these are inside the slider). A couple thoughts. >> >> I don't think pop rivets would fit, and the residual "heads" would be too big. >> >> I was wondering if there is some filler or blend into which I could run self-tapping screws or tap for machine screws. > >The Gougeon Brothers have done a lot of work on "bonded fasteners" (I >think that's what they call it). Basically, it's machine screws or >bolts in epoxy. They have data on shear loads, tension loads, etc. >Gougeon Bros. do not recommend anything without testing and data. They >describe removal (apply head to the fastener) and other operations. As >usual, they have a whole array of filler materials with different >engineering characteristics. > >If by "slider track" you mean the kind of track a sliding hatch runs on, >then you don't need much strength in tension or compression nor much >more in shear. Use some sort of backing plate on a toothpick to hold >the epoxy, fill the holes, drill out for stainless "wood screws" (the >constant-diameter screw that pass for wood screws in stainless these days). > >Chris Campbell >> > > > > > > >