StevedTR4A Posted January 30, 2009 Report Share Posted January 30, 2009 Hi, any paintwork/ restoration experts out there? The body of my TR3A was resprayed in 2 pack signal red over white primer at the completion of a body restoration in 2002. The restoration was completed by the PO to a high standard over a 3 year period as part of a classic vehicle restoration project at a Coventry technical institute. Since then the car has covered 3000 miles and has been garaged for all that time under a muslin ( open weave cotton) dust sheet. I have noticed 4 small clusters of small bubbles in the paintwork on the top of the os rear wing and on the top of the rear apron close to the panel gap with the boot lid. Photos taken during the restoration show that these areas were solid metal before the respray. The photograph shows the worst of the clusters. To give an idea of scale, the panel gap is 4mm. My question is, are these bubbles indicative of lurking rust of could they be from a reaction under the paint from the respray. From what I can determine, these bubbles are hollow. If it was rust underneath, wouldnt the bubbles be solid? I really want to avoid having to rub down these areas and trying to match to the remaining 99% of the paintwork which is imaculate. Do I wto see if it gets worth. - Leave it alone- or take action now. Any comments would be appreciated cheers Steve Quote Link to post Share on other sites
jerrytr5 Posted January 30, 2009 Report Share Posted January 30, 2009 Looks like micro-blistering which I think is caused by moisture in the primer expanding to form a tiny bubble under the topcoat. One of my cars is covered with them Jerry Quote Link to post Share on other sites
RogerH Posted January 30, 2009 Report Share Posted January 30, 2009 (edited) Hi Steve, when did the blisters start to form/be noticed. It could be trapped moisture but if they have only just appeared 6 years is a long time for moisture it to appear. What was the state of the metal work prior to spraying, was an etch primer or other surface protection used. My 4A had 2 pack applied in 96 with a 'perfect' finish within 2 years I noticed 1 blister that has not moved for 8 years. But I also had some blisters and what looked like varicose veins appear on the front of the bonnet and growing at a steady rate. When I sanded back to metal it was indeed rust. I wish I had known about the 'surface protection' service in one of the other posts. Roger Edited January 30, 2009 by RogerH Quote Link to post Share on other sites
stuart Posted January 30, 2009 Report Share Posted January 30, 2009 Bit of a job to tell from your picture as its a bit on the small side but I would say from your description its either microblisters or solvent "pop". Microblisters are a bu**er to get rid of as they are small water droplets coming through the air lines when spraying (poor filtration/damp conditions or too long air lines) may be all the way through to the metal and bare metalling is the only cure. Solvent "pop" is thinners trying to escape when the next layer is applied before the previous coat has flashed off enough and these can usually be flatted off and polished out provided there is enough paint on there. I would be inclined to gently flat the area with 1500 w/dry and then polish up with Tcut and see what it looks like. If the tops of the bubbles come off clean and the primer is exposed then its microblisters so for a temporary fix you could always just touch them in with a very fine brush and then flat off again when dry. However microblisters will always come back unless bare metalled. Shame its 2pack paint as its not really possible to blow in part areas and being seven year old red it will be a difficult one to match. if you do ignore it they will over time develop into small rust spots eventually. Micro blisters are usually found on horizontal surfaces rather than vertical as the water droplets are heavier than spray paint mist and dont tend to make it to the panel from the gun in a vertical plane. Stuart. Quote Link to post Share on other sites
StevedTR4A Posted January 30, 2009 Author Report Share Posted January 30, 2009 Hi Guys Thanks for getting back. I have had the car for just over 1 year. I have only noticed the bubbles recently maybe they were there, possbly smaller but I just had not noticed them. For more clues I will contact the technical institute where the work was carried out and find out what surface preparation was likely to have been carried out. The instructors who supervised the restoration are still there I believe. Unfortunately the PO passed away so the only clues I have are photographs and records of materials. The photos clearly show the panels in these area being rust free and filler free prior to primer being applied. The colour of the primer is white. The material records only show, RM multifill primer, u-pol spray filler, perfection filler. I will though check with the institute. cheers for now Steve Quote Link to post Share on other sites
StevedTR4A Posted January 30, 2009 Author Report Share Posted January 30, 2009 Hi Stuart my reply crossed with your reply. Thanks for the really informative and useful info. I will do as you suggest and see what lies under the surface. Thanks again Steve Quote Link to post Share on other sites
StevedTR4A Posted January 31, 2009 Author Report Share Posted January 31, 2009 Stuart last thought before I go off and tackle the blisters, - rather than rubbing down an area is it worth first trying to deal with individual blisters ie using Kurust and touch up paint with a fine brush and then Langka blob eliminator (which I found on another thread) Thanks for your help Steve Quote Link to post Share on other sites
88V8 Posted January 31, 2009 Report Share Posted January 31, 2009 (edited) Stuartlast thought before I go off and tackle the blisters, - rather than rubbing down an area is it worth first trying to deal with individual blisters ie using Kurust and touch up paint with a fine brush and then Langka blob eliminator (which I found on another thread) Thanks for your help Steve I would always defer to Stuart on such matters, but when dealing with rust - not that my car has any - I would apply Jenolite to 'kill' it. And if you do have to flat, I believe soapy water gives better results than water alone. Not knowing you I wouldn't dare suggest Fairy liquid. Ivor Edited January 31, 2009 by 88V8 Quote Link to post Share on other sites
StevedTR4A Posted January 31, 2009 Author Report Share Posted January 31, 2009 Thanks Ivor Jenolite I have. I'm curious about this "blob eliminator". I have read very good reports about it for dealing with small chips etc so will send for some and try it out. Thanks for the soapy water tip. Steve Quote Link to post Share on other sites
stuart Posted February 1, 2009 Report Share Posted February 1, 2009 I would always defer to Stuart on such matters, but when dealing with rust - not that my car has any - I would apply Jenolite to 'kill' it. And if you do have to flat, I believe soapy water gives better results than water alone. Not knowing you I wouldn't dare suggest Fairy liquid. Ivor Unfortunately "Fairy liquid" has changed formulation some years ago and now you are better off for W/Dry rubbing down using a budget type liquid. As to washing up with it highly recommended Stuart. Quote Link to post Share on other sites
Tom Maddock Posted February 2, 2009 Report Share Posted February 2, 2009 microblistering is caused by residue on the surface between coats stopping the proper adhesion.Whatever you use as a lubricant effective rinsing is essential.I use water that has been via a reverse osmosis filter (RO)and plenty of it.Filler should not be wet flatted as it absorbes water and can cause similar problems to micro blistering but usually larger blisters My 10 pence worth, based on 20 years running my own bodyshop Unfortunately "Fairy liquid" has changed formulation some years ago and now you are better off for W/Dry rubbing down using a budget type liquid. As to washing up with it highly recommended Stuart. Quote Link to post Share on other sites
StevedTR4A Posted February 2, 2009 Author Report Share Posted February 2, 2009 Thanks again for the tips. It really is incredible the knowledge available via this Forum for TR newcomers. I am surprised however that many recent TR converts involved in restorations who I have met recently and who are register members are not aware of the information and useful links that are available. Maybe there needs to be a reminder to members in TRAction that the Forum exists. cheers Steve Quote Link to post Share on other sites
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