Sheeting Foam Wings
04-19-2004, 05:59 PM
#51
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Probond on your fingers??
Hi all,
Just thought I'd toss one in here...
If you get PROBOND on your fingers....
Quickly grab the wife's fingernail polish remover....(lemon scent is best, otherwise you may smell like some variation of flower) and a cotton ball.
Takes it right off...and doesn't leave sticky brown spots...
Good Luck...
I've used Probond (Ultimate Glue) with great results...
I've eyeballed the Sorgum at the hobby shop...cause it's cheap....but haven't tried it....maybe worth a "test" sometime....
Wouldn't mind trying the FoamBond stuff either.....NWHobbyTech planes look cool...
CrazyHerb
Just thought I'd toss one in here...
If you get PROBOND on your fingers....
Quickly grab the wife's fingernail polish remover....(lemon scent is best, otherwise you may smell like some variation of flower) and a cotton ball.
Takes it right off...and doesn't leave sticky brown spots...
Good Luck...
I've used Probond (Ultimate Glue) with great results...
I've eyeballed the Sorgum at the hobby shop...cause it's cheap....but haven't tried it....maybe worth a "test" sometime....
Wouldn't mind trying the FoamBond stuff either.....NWHobbyTech planes look cool...
CrazyHerb
04-19-2004, 06:25 PM
#52
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RE: Probond on your fingers??
Crazy Herb, iso alcohol or starting fluid (ether) work great for cleaning up Poly glue off the fingers, workbench, etc also. Thanks for the acetone tip, I'll remember that next time I run out of the other stuff.
09-01-2004, 12:17 PM
#53
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RE: Probond on your fingers??
Yeah Baby! Ether is great stuff. You'll be floating around the shop like you're walking on air after you get all cleaned up! LOL Personally, I stick to acetone. If you've messed with race cars and ether, you know how explosive that stuff is. I won't even keep that stuff in my shop anymore. Too dang explosive. If I need starting fluid I just use gas or alcohol or nitro. If that won't start 'em, then something is wrong. heh
11-17-2004, 02:35 PM
#54
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RE: Sheeting Foam Wings
OK all you vacuum bagging experts...let me know your opinion here.
I recently received one of ACP's vacuum pump starter kits to use on my winter building project. The other night I decided to "practice" sheeting a piece of foam with some scrap balsa before I try sheeting the real parts and screw something up. Here's what I did:
I used some old scrap pieces of 1/16" balsa sheet, edge trued them, taped them together to fit the foam part. The foam part is a leftover piece of hatch-cover a buddy of mine had laying around. I thought it would be a perfect practice piece
I spread a very thin layer of ProBond over the wood...scraping off as much as I could so that the wood had a satin finish...didn't look wet.
I then put the wood and foam piece back in the shuck and put the whole assembly into the vacuum bag and let the pump do it's thing.
When I assembled the bag, I only put a small piece of breather material under the tube fitting....not all the way under the foam part. The pump is also preset to deliver 7" of vacuum. I let everything set for 24 hours.
When I took the part out of the bag, everything looked great...and I was pretty pleased with the results. However, I did find one area along the tightest curve of the foam where the wood never bonded to the foam. I actually noticed this while it was in the bag. The wood didn't want to bend tight enough to sit on the foam. I tried to coax it into position but was afraid of cracking the sheeting.
So I guess my question is, is this normal? Should I be concerned about small areas like this that don't bond well? If it will cause problems, what is the best way to fix it?
I don't think it will be a problem on the wings and stabs as the wood won't have to conform to as tight of a curve as my test piece.
I recently received one of ACP's vacuum pump starter kits to use on my winter building project. The other night I decided to "practice" sheeting a piece of foam with some scrap balsa before I try sheeting the real parts and screw something up. Here's what I did:
I used some old scrap pieces of 1/16" balsa sheet, edge trued them, taped them together to fit the foam part. The foam part is a leftover piece of hatch-cover a buddy of mine had laying around. I thought it would be a perfect practice piece
I spread a very thin layer of ProBond over the wood...scraping off as much as I could so that the wood had a satin finish...didn't look wet.
I then put the wood and foam piece back in the shuck and put the whole assembly into the vacuum bag and let the pump do it's thing.
When I assembled the bag, I only put a small piece of breather material under the tube fitting....not all the way under the foam part. The pump is also preset to deliver 7" of vacuum. I let everything set for 24 hours.
When I took the part out of the bag, everything looked great...and I was pretty pleased with the results. However, I did find one area along the tightest curve of the foam where the wood never bonded to the foam. I actually noticed this while it was in the bag. The wood didn't want to bend tight enough to sit on the foam. I tried to coax it into position but was afraid of cracking the sheeting.
So I guess my question is, is this normal? Should I be concerned about small areas like this that don't bond well? If it will cause problems, what is the best way to fix it?
I don't think it will be a problem on the wings and stabs as the wood won't have to conform to as tight of a curve as my test piece.
11-18-2004, 01:06 AM
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RE: Sheeting Foam Wings
I prefer the shucks outside the bag. I use one shuck underneath, and light sandbags on top.
The sandbags ensure the wings cure flat.
With the sheeting and core only in the bag, the vacuum is sure to pull all the sheeting towards the core.
The sandbags ensure the wings cure flat.
With the sheeting and core only in the bag, the vacuum is sure to pull all the sheeting towards the core.
11-19-2004, 08:36 AM
#56
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RE: Sheeting Foam Wings
OK, I tried this method last night. I also used just a tiny bit more glue on the wood. This piece looks better than the first...all the wood everywhere that I've checked is tight against the foam, and the glue looks like it really penetrated the foam for a better bond.
I did have to be careful at the start though, because the bag wanted to suck down between the wood and the foam along the seams. I was able to pull it out though and everything was fine. Looks like I'll just need to check the piece very carefully when vacuum is first pulled on production pieces.
I think I'll use this method from now on. Thanks!
I did have to be careful at the start though, because the bag wanted to suck down between the wood and the foam along the seams. I was able to pull it out though and everything was fine. Looks like I'll just need to check the piece very carefully when vacuum is first pulled on production pieces.
I think I'll use this method from now on. Thanks!
ORIGINAL: patternwannabee
I prefer the shucks outside the bag. I use one shuck underneath, and light sandbags on top.
The sandbags ensure the wings cure flat.
With the sheeting and core only in the bag, the vacuum is sure to pull all the sheeting towards the core.
I prefer the shucks outside the bag. I use one shuck underneath, and light sandbags on top.
The sandbags ensure the wings cure flat.
With the sheeting and core only in the bag, the vacuum is sure to pull all the sheeting towards the core.
11-19-2004, 01:49 PM
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RE: Sheeting Foam Wings
Glad to have helped.
As long as the bag doesn't get between the foam and the sheeting, you're good.
If you use a rather thin bag, say 1.5 mils or so, the ability of the bag to fold into the contours can be an advantage. For instance, at the trailing edge, if you have 1/4 overhang, the plastic can find its way between the upper and lower sheeting (but not between the sheeting and the foam). If not, there is a void, the vacuum can crach the sheeting.
As long as the bag doesn't get between the foam and the sheeting, you're good.
If you use a rather thin bag, say 1.5 mils or so, the ability of the bag to fold into the contours can be an advantage. For instance, at the trailing edge, if you have 1/4 overhang, the plastic can find its way between the upper and lower sheeting (but not between the sheeting and the foam). If not, there is a void, the vacuum can crach the sheeting.
11-19-2004, 01:56 PM
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RE: Sheeting Foam Wings
wy metod :first I keep toghether the balsa sheets with adesive tape, then I apply thin cyano on all junctions, once the glue is dry I remove the tape and sand both sides wih a sanding block made of foam and rough sand paper, then I keep toghether the two skins(upper and lower) with many pieces of tape on trailing edge( to form it) I spread a little water on the balsa ,poliuretanic glue, place the core in the middle ......a lot of weight and after about 5 hours the balsa is perfetcly bond to the foam. if you cut the wings with built in dyedral you can also join the cores before sheeting and include the fiberglass between foam and balsa.
11-29-2004, 10:11 AM
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RE: Sheeting Foam Wings
Ok guys,i'm gonna add a little fuel to this discussions fire. 
I've used all of the products mentioned in this thread,and from personal experience i can say NONE of them work as good or as fast as 3M 77 spray adhesive! With all those other products you have to worry about drying time,the panels warping or moving the sheeting and you cant touch them for 12 to 24 hours. To SLOW for me! With the 3M spray,i just cover the foam and skin in a thin coating,let set for a smoke break ( 5 minutes) then line them up on the leading edge and roll the foam onto the sheeting! Bang! one sides done,i do the other and in less the 20 minutes,both wing halves are fully sheeted and i start putting on the le and te stock. In about a hours time,i have 2 complete wings ready for covering! And as some of you are no doubt going to say,well in different climates that stuff will come lose or warp over time. Well i'm here to say,i've lived in colder climates ( up state NY ) and hotter ones ( south TX ) and have NEVER had any sheeting come apart or bubble up from the foam. The only down fall to the 3M 77 spray is this, MAKE ABSOLUTELY SURE you position the foam on the sheeting EXACTLY where you want it! you only get 1 shot at it,cause if you miss,you AIN'T GETTING THEM APART for a second try!
Good luck all
I've used all of the products mentioned in this thread,and from personal experience i can say NONE of them work as good or as fast as 3M 77 spray adhesive! With all those other products you have to worry about drying time,the panels warping or moving the sheeting and you cant touch them for 12 to 24 hours. To SLOW for me! With the 3M spray,i just cover the foam and skin in a thin coating,let set for a smoke break ( 5 minutes) then line them up on the leading edge and roll the foam onto the sheeting! Bang! one sides done,i do the other and in less the 20 minutes,both wing halves are fully sheeted and i start putting on the le and te stock. In about a hours time,i have 2 complete wings ready for covering! And as some of you are no doubt going to say,well in different climates that stuff will come lose or warp over time. Well i'm here to say,i've lived in colder climates ( up state NY ) and hotter ones ( south TX ) and have NEVER had any sheeting come apart or bubble up from the foam. The only down fall to the 3M 77 spray is this, MAKE ABSOLUTELY SURE you position the foam on the sheeting EXACTLY where you want it! you only get 1 shot at it,cause if you miss,you AIN'T GETTING THEM APART for a second try! Good luck all
