How strong is the Q-Bond joint compared to a sewn seam?
The test made at the technical university shows 2 to 5 times stronger resistance to shear stresses. Download the full test report
How about UV-stability and durability?
The test made at the technical university shows when the UV-light had destroyed the tread in the seam we still had 50% of original strength of the Q-Bonded joint.
How long time this is in years depends on UV-light intensity where the sail is used.
Several Volvo Ocean Race teams used Q-Bonded sails without rupture of the joints during the races. The UV-exposure during these races where very high and long compared to a normal sailors usage of the sails.
About the various yarn materials
What difference is it between activating Pentex, Kevlar and carbon fibres?
Pentex, a polyester fibre, is quite sensitive to heat, with higher tendency to shrink during the ultrasonic activation compared to Kevlar/aramide- or carbon reinforced laminates.
Activation must be done at lower temperatures. We advice sail makers to start their practice with aramide laminate as they are the easiest to learn to handle.
Laminates with carbon fibres do often have the carbon yarns in bundles not impregnated with lamination adhesives. This means a lot of air in the fibre bundles. A lot of air means a low ultrasonic heating in the laminate with resulting low speed activation.
How old tape can I use?
See the expiry date of the tape bag. The tape can however be used as long it is really sticky as well chewed chewing gum.
For how long time can I use an opened Q-Bond Tape?
It depends on the temperature and moister content in the air, but usually during the same day of opening. If you have tape left when the assembly is finished, put the tape role in the airtight back and seal the bag. Put the bag in the refrigerator and use it the day after. Check it is room temperature and sticky before you use it.
How long time do I have to wait for curing before using the sail?
This also depends on the temperature during the curing process. We usually consider 3 days curing time enough it the sail is not going to be used in very strong windy conditions.
Do I need to spray each Q-Tape with water?
Yes, water is the curing agent of the adhesive in the tape. One other possibility is to spray one panel with water mist and have the opposite panel taped, then press the panels together. Water sprayed panel sid towards the Q-Bond glue.
How do I activate a laminate with various yarn content and yarn type in the same panel?
This can be the case with panel sails like the D4 from Dimension-Polyant and similar Keep control of the surface temperature and alter the activation speed. At certain parts with high yearn content the built up heat is higher than at parties with low yarn content. You need to run the activation faster at parties with the high yarn content and vice versa. If you are uncertain to the chewing gum test to obtain the right temperature and speed.
How do I not overheat multiple layers of fabric in reinforcements (clew, tack and head)?
Multiple layers of sail fabric tend to build up more heat the thicker they are. The temperature meter will only show you the outer surface temperature of the outermost layer. This means a considerable high temperature can be obtained in the middle of several layers of sail cloth. Do the activation on a test sample with the same amount of layers using the same laminate. Do as in the chewing gum test to control the glue in the Q-Bond Tape sticks to all sides in all layers. Usually you can activate 3-4 layers at the same time running quite fast with the activation unit.
Can I activate the joint several times?
Yes, but be careful with overheating Pentex laminates.
At what temp does the Mylar film shrink?
Mylar films and other polyester films start to shrink at approximately 190 degrees Celsius. Usually the temperature of the glue inside the joint is 2-2,5 times higher than the surface temperature. This means avid overheating by activate at a lower temp than 75-80 degrees Celsius
Can I open and adjust a new made joint?
Yes, you can directly after activation, when you have checked the shape of the sail, open a joint, correct the shape and close the joint again. Now you need to activate again.
Can I open and adjust a cured joint, being 3-5 days old?
Yes, by warming up the joint in small sections 20-30 cm long you can carefully open a joint. First take away the covering Mylar Tape from both sides of the joint, then use a soft knife, spatula to carefully open the joint. Be careful not the over stretch the fibres in the laminate with a permanent distortion as effect. You must ad new Q-Bond Tape and activate the joint again.
How to increase activation speed of the mobile unit?
There are several ways to increase the activation speed. The speed is directly proportional to temperature build up in the laminate.
Longer cable
Is it possible to get a longer high frequency cable from to ultrasonic generator to the cutter or mobile activation unit?
No it is not. The energy losses in the cable will be to high. Instead you have to put the generator on a small trolley and use an extension cable to the 220VAC feeding the generator.
FAQ about the ultrasonic cutter
Why is it not cutting so fast any longer?
You need to clean the area around the knife’s edge, and between the edge and the hard metal base plate. Use a stiff brush to get rid of dust and fibre residues.
I have cleaned the cutter but it still not cuts well enough?
When you cleaned it, if you loosen the fixation umbraco screws is it then correctly assembled? Check in the manual.