Vibration use?

[SGT]

Originally Posted by Guelster

OK splitpit Kudos to you!
I have been punching star breaks in this practice windshield I have all week. To be honest I have been having trouble filling tight legs in them. I just ran out to the garage and tried your way...believe it or not I think it did work. I had this star with 8 legs....4 of which were very tight. I put the big felt pad on a 10.8v dremel and powered that thing up to about 5 (10 being the highest). While pressing in from the insdie part of the windshield I rolled the tip around the break. Surprisingly enough it filled those tight legs. I will try more tomorrow and post the findings.
Thanks so much for this tip!

Are you sure the legs filled with resin or did they close due to expansion?

Becareful to not generate to much heat with the dremel(friction) or any source for that matter as this could close off the legs prematurely providing a false sense of fill. Especially tight fractures. Just something to consider.

[splitpit]

Heat would not be an issue when it comes to the use of the device that I mentioned. Vibration only. Also, flexing the legs in a normal procedure may still be necessary.

[splitpit]

On the topic of the use of heat, he also mentioned that he uses what he calls "pulse heat" rather than steady heat when he does need to heat up a repair. He agreed that any use of heat should be avoided as much as possible though.
His pulse heat procedure was described as this: he uses small short flicks of a lighter with slight pauses in between while carefully watching the damage. At the first sign of movement, he stops heating. He says this eliminates overheating and excessive expansion.

[screenman]

I would only heat until I see movement and no more, the reason being that the damage area will keep getting hotter for a short while after you remove the heat source. This is due to the fact that the heat has to travel through the glass. As for vibration I have never found the need for it, I have tried and experimented with it but have found it does not improve my normal techniques.

[screenman]

I might be wrong here but did 3M not have a repair system in the very early 70s that used to vibrate the whole shield. I am sure I remember something somewhere hopefully there are some older or more knowledgeble guys on this site that might tell us more.

[SGT]

Sorry I do not know the 3M system you mention but I do consider myself part of the "younger more knowledgeable guys"

I am a big fan of the Bic lighter and the radiant heat it gives off. I use it in conjunction with my Mini Raytek to monitor windshield temp. as it rises. Depending on how you move the flame and or how far you hold the lighter away, you can have the desired rate the temp. will rise. I like to get it between 70-90 deg. IMHO a Bic lighter and a temp sensor shouold be in everyones tool box. Supper easy technique and very effective.

Some may disagree here, but if you have your injector tip pressure set right, you can heat during vaccum or pressure cycles. I do it all the time. Did I just jinx myself?

Maybe the heat thing should be in a different thread.

[screenman]

The first company to produce a repair system was Minnesota Mining and Manufacturing (3M) Company in St. Paul, Minnesota. The 3M Company first introduced a system they called "Scotch Weld" in 1971. This system employed ultra sound vibrations to clean the break and a syringe to inject a resin, or adhesive into the damage. The equipment successfully repaired "bullseye" type damage, but unfortunately was very large (filling the bed of a pick-up truck) and was very expensive to build and thus to lease to others. It is said that 3M did a good job of introducing the concept of windshield repair to insurance companies, but decided to pursue other products when the repair equipment failed to attain the volume that they required.

Why would you want to heat under pressure? I know that for a very short time the damage can open up but not long enough for any resin to penetrate very far. Since I changed to Magnibond I have not had to use heat to fill a star break once.

[SGT]

When I say I do it all the time I should have followed it with "when necessary". I do not use heat on every repair for the purpose of resin flow. I knew the comment would get a little attention. I have not had one run on me yet from this! If you are only using enough tip pressure to prevent a leak at the seal and you do not use extreme heat, you should have no problem. Common sense should be applied based on the break.

Where I live it gets pretty cold so in the winter I use this technique more often to warm up the windshield or keep it between 70-90 deg after using the moisture evaporator during the repair.

Magnibond is great resin, in fact I just purchased a litre but sometimes there are breaks that just wont fill, in which case you need use various techniques to achieve a structurally sound repair.

[splitpit]

Wow, I heard an echo!

[jayjacque]

I like heat. It's my friend. There I said it. I'm not using magnibond YET. We'll see if trying that changes things, but as it is, a little heat is sometimes (maybe more than just sometimes) just the thing to complete a repair. Also sometimes I do my own little shake and dance out in the parking lot when I can't get a leg to fill. Is that what you mean by shaking? LOL