I want to drill a 3/16 ” hole through the entire width of a piece of styrofoam that is 12″ wide and 1/2″ thick. I then want to run a 3/16″ wooden dowel through the width in order to reinforce the styrofoam and attach it to something. I don’t have a drill 12″ long and don’t want to buy one even if they are on the market. Does anyone know how I could make such a deep hole?
Thanks.
Replies
You could use the dowel to drill the hole couldn't you. it's just styrofoam.
it would be easier to buy two 1/4 foam sheets and place your dowel between them in a groove then to bore a hole in that messy stuff.
Now thats what I call thinking "out of the box"!!!!!!!!
PlaneWood by Mike_in_Katy (maker of fine sawdust!)PlaneWood
Take a 3/32" welding rod, heat to 400-500* then stick it through. Follow with the dowel.
Put a point on the dowel with a pencil sharpener and push it through. Cut the sharp end off after it's through.
Len
I would take a 3/16 steel rod, heat it in the oven just enough so that it would melt the styrofoam and then push it through. A welding rod would have flux on it that might cause some problems. hope this helps
Andrew
If you heat a 3/16 rod your hole will be larger than 3/16 . The heat keeps on drilling after it has reached its clearance.
Apointed stick will tearand push of to one direction or the other.
When you do have to make your own bellhangers bit in a size not commercially available, pick what you need out of this piece I did on repairing cracked transoms.
Transom Cracked
Go to Brownells.com and gander at their #080-565-000 Stock Repair Pin kit. I haven't found anything quite like it elsewhere.
2.5" long threaded brass pins...if you need longer, silverbraze bronze or brass extensions on them from rod stock.
Buy their bottled silverbraze ground in flux, a machinist's V-block or two for a jig and a MAPP gas kit from Home Depot and that, too will be easy. Clean faying surfaces, dab on some braze, lay in the jig and heat. Chalk the V-block heavily to keep the braze from sticking to your jig. Takes 1100 degrees...a dull red...stop when the silver flows freely.
To clean the braze joint and insure your tacked-on extension is a couple thousands smaller than the thread OD, chuck the nonthreaded end of your assembly in a variable speed drill, poke the threaded end in your shop wall for support, and slowly spin while laying a single-cut mill file atop.
Remove motor. Clean crack thoroughly with acetone and blow dry with serious compressed air. Epoxy and clamp that crack up as tight as you can with padded large door clamps.
Use 4-1 or 5-1 marine epoxy like West System (not household 1-1 epoxy), get their booklet and follow the instructions. At the end of the crack, heat gently with a heat gun or lamp...no more than 110 degrees...to get it to seep into the end of the crack too narrow for your spatula. Brownell's sells a more-expensive "Acraglass" that probably comes out of the same tank.
Make beveled pads for bottom planking and coved or dado'd pads for transom top and do a dry run to check clamp fit before gluing.
Drill pilot holes for these shallow-threaded brass drifts per instructions...use a helper to sight and correct your side angle while you sight perpendicular as you drill...coat with epoxy, and run them in with your drill at slow speed. Leave on clamps for 24 hours. Clean squeezeout with a vinegar-dampened rag. One drift every 3-5 inches. Trim, bung and finish, and it'll likely last the life of the transom.
If you need a longer drill...and bell-hanger bits in those small sizes are hard to find...use the same brazing technique with some drill rod.
Use a drill with centerpunch to recess the trimmed drifts for bungs. Match the grain of the bungs, and blend in the edges with appropriate stains, and you won't find your repair unless you know where and what to look for.
I'd also look to reinforce that transom better on it's inside face to accommodate the motor...that board cracked for a reason. 150lbs on the motormount seems like an awful lot of weight for a 13' boat. Bet it was designed for only half that.
Bill9,
I think that all of the suggestions, with the exception of the idea of sandwiching the dowel between two sheets of 1/4 inch stock, miss the basic problem.
Drilling or melting a hole in Styrofoam is easily done a dozen different ways, getting the hole to go straight through the thin sheet and not veer off and come out through the face of the sheet half way across is the hard part.
The two layer method would solve that problem. Another way to do it would be to saw a groove in the foam, press in the dowel, and then fill the groove with a glued in thin strip of wood (hobby shop balsa strips would work well) or fill the groove with a setting type of filler such as a silicone caulk.
If the dowel is going to be close to one edge, you could cut the groove in the edge rather than the face of the foam, this would be stronger and less obvious.
Hope this helps, John W.
OK, I've rethought the problem and now have a solution. Make a perfectly srtaight hole in milliseconds by shooting it with a .22 cal short.
Use a CB cap and back it up with a phone book and you can do it in the shop.
BTDT.
I figured Bill9 wouldn't have CB or BB caps, since they're hard to find in some areas.
Walmart, here....but we're just joking, right?
Thanks. I'll check Walmart. I'm building a 5/8 scale model of the Browning M1919 A6 that shoots CB caps and didn't have a source of ammo supply. Did a 1/2 scale of the Thompson M1921/28 a while back in .25ACP but it was too damn expensive to shoot.
I'm impressed...I was an on-and-off stockmaker for a number of decades.
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