Brad Ridgway
07-04-2009, 7:19 AM
i've been needing/wanting an assembly table for a while as i have nothing flat / large enough in the shop and assembling on my garage floor was getting old. all day yday and i've now got the basics done - just shy of 4x8 with the skins attached. not sure where its going or how i'll move it around in my small shop, but thats besides the point.
i had gone to the trouble of drilling holes in all the ply pieces for the grid to allow me to attach my vacuum pump for more clamping pressure while i screwed down the skin. i attempted to seal the gaps with tape all around both skins where they met the grid and figured there was roughly 6 cubic feet to remove. I have an old thomas pump that i was sure specs could pull 3cfm in Joe's setup. Anyway it would never create a vacuum and i let it run at least 10 minutes.... i could not feel/find a leak anywhere, but i'm guessing there was one somewhere... so weight & screws ended up being my only clamping pressure.
Anyway. pretty good experience, though the top isn't dead flat throwing a straighedge across reveals some slight dips (guessing <1/32?) but not real bad (they are from inaccuracies in ripping the core strips) as i had a very flat /level base for assembly. i'm thinking i'll fold up some foil to shim the hardborad top that goes on top to get it really close...
if only i could find some cheap hardwood to skirt it
questions:
1) the hardboard is only 3/16... i'm slightly worried if i try to countersink screws that its not going to come out well... should i brad nail only in a few spots? i do want it replaceable as in the woodwhisperer design...
2) was thinking that some kind of leveling compound on the top skin would be great. I don't want the stuff they make for concrete floors (but same idea) but anything else (of ahobby/craft variety) that could flow and adhere to mdf and dry solid and flat to remove those minor dips?
3) i think the torsion construction would allow me to store on the long edge without any tendency to bow / warp... anyone feel otherwise (esp if that happened to be for long periods)?
i had gone to the trouble of drilling holes in all the ply pieces for the grid to allow me to attach my vacuum pump for more clamping pressure while i screwed down the skin. i attempted to seal the gaps with tape all around both skins where they met the grid and figured there was roughly 6 cubic feet to remove. I have an old thomas pump that i was sure specs could pull 3cfm in Joe's setup. Anyway it would never create a vacuum and i let it run at least 10 minutes.... i could not feel/find a leak anywhere, but i'm guessing there was one somewhere... so weight & screws ended up being my only clamping pressure.
Anyway. pretty good experience, though the top isn't dead flat throwing a straighedge across reveals some slight dips (guessing <1/32?) but not real bad (they are from inaccuracies in ripping the core strips) as i had a very flat /level base for assembly. i'm thinking i'll fold up some foil to shim the hardborad top that goes on top to get it really close...
if only i could find some cheap hardwood to skirt it
questions:
1) the hardboard is only 3/16... i'm slightly worried if i try to countersink screws that its not going to come out well... should i brad nail only in a few spots? i do want it replaceable as in the woodwhisperer design...
2) was thinking that some kind of leveling compound on the top skin would be great. I don't want the stuff they make for concrete floors (but same idea) but anything else (of ahobby/craft variety) that could flow and adhere to mdf and dry solid and flat to remove those minor dips?
3) i think the torsion construction would allow me to store on the long edge without any tendency to bow / warp... anyone feel otherwise (esp if that happened to be for long periods)?